Wednesday, June 6, 2018

SearchResearch Challenge (6/6/18): Seed dispersal mechanisms for giant seeds? (And search strategies)

I'm back! 

Welcome to the new post-book SearchResearch.  Just so you'll know, it's provisionally called The Joy of Finding Out.  

A quick book update:  I finished the first draft of the manuscript.  Now comes the copyediting, approvals, publisher comments, figuring out the color pages, etc etc.  One of my friends who's an accomplished author said "Congratulations.. now the work begins!"  

Ummm.... What was all that stuff I just did? 

When this thing is all done, I'll give you a bit of a breakdown in terms of effort--how much time was spent writing, how much time editing, etc.  

Realistically, this book is probably a 2019 publication.  (But I'm hoping for an earlier, limited release!)  Stay tuned. 

I know I promised you a  breakdown of the survey results from last week, but I'll get to that tomorrow.  There were a LOT of insightful (and lengthy) comments--it's a bit more than I can whip out in just an hour or so.   So I'll give you a new Challenge for this week, and give a summary of the survey tomorrow.  

WHILE I was working on the book, I ate a lot of the millennial's favorite, avocado toastSince I live in California, I usually just make my own avo-toast at home, which means I look at a lot of avocados.  

As I was tossing one into the compost bin I started to wonder about the seeds and how the avocado seed is dispersed in its natural habitat.  Since I used to live in Los Angeles, I've seen a lot of avocado trees. They get pretty big and can have a thousand avocados on their branches.  But when ripe, they just plummet straight down.  Let me tell you, it can get really messy down there.  

They're pretty easy to grow, but how does an avocado get around?  I mean, are there forests of avocados??  

That led to me today's Challenge: 

1.  How are avocados dispersed?  If they rely on just falling from the tree, that doesn't seem to work well... so is the "natural" dispersal by animal?  If so, WHAT animal would eat an avocado... and then be big enough to carry it somewhere and leave it behind in a new place?    
2.  Are there other plants with giant seeds (like the avocado's) and how do THEY get dispersed?  
3.  In writing this post, I’ve been looking for an early illustration of an avocado.  It's kind of tricky.  What’s a strategy for finding the earliest illustration of something?  In our case, an avocado seed... but how about finding an early illustration of ANY thing?  

Once you figure out the answer, let us know... AND be sure to tell us HOW you figured it out!  

I'm curious to see what your "old illustration" strategies will be.   

Search on!  (And keep eating avocado toast.  The avocado ranchers need your support.) 


  1. Good day, Dr. Russell and congratulations on your book. If the hard part is just beginning, I am sure also the fun one is also starting. Writing is, for me, the hardest or at least the one you need to think, work, write and start the process again. The next part, is just making it more beautiful. It is hard work, and at least now you have something real that keeps you moving forward. Congratulations.

    About seed, great question! I didn't think about that. I know there are places like have plenty of avocado trees but that question is very interesting.

    Related to the topic, I was thinking yesterday why a peach tree (which also has a hard seed) grows faster and gives much more better food and with more quanity when the seed is moved by the birds.

    We had three peach trees that grew very slowly and suddenly, others grew in other places no near to the first ones. And they give more fruit and better one. Plus they give fruit each year. And the original 3, just a few fruits and not annually. I wonder why, and how we could search that phenomenon

  2. 1. How are avocados dispersed? If they rely on just falling from the tree, that doesn't seem to work well... so is the "natural" dispersal by animal? If so, WHAT animal would eat an avocado... and then be big enough to carry it somewhere and leave it behind in a new place?

    [how avocado seed gets dispersed]

    What was the seed dispersal mechanism for avocados before humans began cultivating them?
    The ingenious ways plants disperse their seeds

    Why the Avocado Should Have Gone the Way of the Dodo
    A: Megafauna
    B: Evolutionary anachronism
    C: In California for the first time in 1914. Today 90% of USA Avocados comes from California
    D: Mentions other fruits

    Evolutionary Anachronisms
    New word for me: “Endozoochory”

    1. [Cómo se propaga el aguacate]

      link text Includes video “Ghosts of Evolution” by PBSand mentions a book too.

      Searched for the book on Google Books and also [Ghosts of Evolution avocado]

      "The Botanical Ghosts of Evolution"
      by Connie Barlow a contribution in Forest Canopies edited by Bruce Rinker and Meg Lowman, 2004

      [seeds dispersal similar to avocado]

      Other evolutionary abandonees include the osage orange, the papaya, the honey locust, and the tam tree of the island of Mauritius Mentions Jaguar and Squirrel theory, mentioning “This is hardly a reliable seed dispersal system.” And, says “ The avocado’s real savior was hungry humans”

      As I found mangoes are also an anachronism, searched [Mango seed dispersal]

      Decided to try a site that has good research:
      Today I found out about avocados From their sources found

      Dr. Russell’s avocado “forest” image and learned: “The Hass Avocado is a California native. The Hass variety was discovered in La Habra Heights, California, in the 1920s by Rudolph Hass. In fact, every Hass Avocado in the world can trace its lineage to the original Hass Mother Tree.”

      Avocado history. No mention of seed dispersal

      [pineapple seed dispersal] thinking about previous SRS Challenges

      Fruit and Plant Dispersal
      How Do Pineapple Plants Reproduce?

      The pineapple fruit grows out of the top of the central stem. The fruit is actually the result of dozens of individual fruit-producing flowers that have fused into a single fruit

      Looking for illustrations found this with [most ancient avocado seed] also read about a dormant seed from 850 years ago (not avocado) that is now alive.


    2. 3. In writing this post, I’ve been looking for an early illustration of an avocado. It's kind of tricky. What’s a strategy for finding the earliest illustration of something? In our case, an avocado seed... but how about finding an early illustration of ANY thing?

      First [Define illustration] to verify if what I think was the same thing you/we are looking for.

      Then [illustration database] and [how to find free illustrations]

      The 22 best places to find free vector art online (january 2018)

      With that in mind, went to Google Search Images and in tools there are 2 options: Clip art and line drawing. And then used search tool time, custom range. Not results.

      Also noticed [ avocado illustration 1900..1940] gives many images and [avocado illustration, search tools, time, custom range 1900 to 1940] gives zero results

      [Clip art vs Illustration]

      Types of Illustration – Styles and Techniques so I am sure Dr. Russell wants a way to find not just clip art and also this works for present day or recent. Searching early has been hard to find.

    3. Unrelated to this Challenge but at same time related with others and with Hawaii: this article It is very interesting and the author mentions other Twitter users added data to him, so maybe if Dr. Russell or any of us has questions, doubts or suggestions, he could answer and add those to the article. In my case, I didn't know much about the science behind the story nor how to calculate, therefore, everything is new and fascinating.

    4. 2 more articles unrelated to SRS Challenge of this week. And also related to previous SRS Challenges

      A billionaire venture capitalist's bid to split California into three separate states has earned a spot on the ballot in November's mid-term elections. There have been over 200 attempts to divvy up the state by lawmakers, counties and well-off individuals like Mr Draper since California was founded in 1850...For now, the move is still a long shot, especially given its history. But on 6 November, Californians will have a chance to weigh in on the matter...

      I didn't know about this piece in some human's ears El seno preauricular: ¿por qué algunas personas tienen un orificio en la parte superior de la oreja? article in Wikipedia (Preauricular sinus and cyst)

  3. 1. I actually knew this because of a podcast I listened to, but just to confirm with the interwebs:
    [avocado seed dispersal]
    This led me to the charmingly-titled "Shit You Don't Know About Biology" which introduced me to the concept of "endozoochory" (seeds being carried inside an animal's gut). The article states that the animal that performed this task is now extinct, and that the main current consumers (monkeys) don't help, as they throw the seeds back at the parent tree. So, what was this extinct animal?
    [avocado seed dispersal animal]
    This led to U Berkeley's EvoLibrary: which posits that avocados were dispersed by herbivorous megafauna, like giant ground sloths. These went extinct during the ice age, which the avocado managed to survive. After this, it was humans who took up the slack with early agriculture.

    2. There are plenty plants with large seeds!
    [largest seeds]
    This brings us to Wikipedia:
    There isn't enough time in my lunchbreak to do them all, so I just did the first.
    [coco de mer seed dispersal]
    This resulted in a great article from New Scientist:
    TL;DR - they used to be dispersed by animals, but no longer, and the unusually large seeds mean they can't be carried by the wind. So, now the plants are isolated to two islands, and the seedlings actually thrive in the shadow of the parent plant!

    3. [earliest illustration] leads to the Wikipedia page on "Illustration" which says that early illustrations were called "illuminations"
    [avocado seed early illumination] in Image Search doesn't give any good results.
    [avocado seed early illustration] results in an early seed catalogue page from 1918, but it's all photographs by then:
    In short, I think I'm stumped on this one.

    1. Trying your query and adding [avocado seed early illustration|illumination ] found

      How a prehistoric fruit wound up at your Super Bowl party

      Interesting among many:

      1. "An American "food spy" named David Fairchild, on assignment for the U.S. Department of Agriculture, picked up the fruit in Chile in the 1890s with the intention of introducing it to U.S. farmers and American palates."

      2. "Avocado toast" didn't come up until 2013. Dr. Russell, is this real?
      3. Netherlands consumption is growing

    2. Looking for the Q3 answer, searched in Spanish with queries like [ How to find illustrations from past centuries] [how to search illustrations from past centuries] [Illustrations from the past] [Illustrations from #..#]

      And found this site with some old and some new sources for me. It doesn't give answer to Q3 but helps to have more tools

      Los mejores bancos de imágenes históricas y gratuitas

      Flickr Commons, The Internet Archive Book Images, The Library of Congress, The British Library,Smithsonian Institution, NASA, George Eastman House, New York Public Library, San Diego Air & Space Museum Archives, The National Archives UK, Bibliothèque de Toulouse, Biblioteca de Arte / Art Library Fundação Calouste Gulbenkian, Metropolitan Museum of Art, Europeana, Biblioteca Nacional de España,Rijksmuseum (Netherlands),Museo de la Ciudad de Nueva York,

      and looking for the word "bancos de imágenes" in English found this one. I used word image depositories, not sure is the right one.

      2009: 12 best places to get free images for your site

  4. The response I sent in yesterday seems not to have made it. It may have been too long ... so I'm re-sending in two parts. There will be some overlap with the others.

    1) A simple search for [avocado seed dispersal animal] turns up some fascinating sources that say avocados are indeed evolutionary anachronisms, in that the large "megafauna" animals that once ate and dispersed their seeds are now extinct.

    These sources include:

    Smithsonian article "Why the Avocado Should Have Gone the Way of the Dodo" (Oct. 24, 2013):

    UC Berkeley article, "What happens to plants that can't spread their seeds?" (December 2015): ... which mentions the origin of the term "evolutionary anachronism" -- a 1982 Science paper by Daniel Janzen and Paul Martin ("Neotropical anachronisms: the fruits the gomphotheres ate." Science. 1982 Jan 1;215(4528):19-27. )

    > > >
    In the paper, Janzen and Martin describe anachronistic plants as those with traits that once enhanced dispersal and increased fitness, but that are today no longer adaptive because the plants' main seed-dispersers have gone extinct. For an example, you needn't look further than the everyday avocado. An avocado plant produces fruits with massive seeds. There is no wild animal (except humans) in the avocado plant's native Central America that can disperse avocado seeds today. But that wasn't always the case. Go back between 125,000–11,000 years ago and you'd find that ecosystems in the Americas were populated with some very large herbivores — members of a group known as the Pleistocene megafauna.

    Megafauna translates literally to "big animal." Here, I apply the term to land animals with masses greater than 1,000 kg (about 2,000 lb.). By this definition, elephants are the only examples of living megafauna, but before the end of the last ice age, megafauna were far more diverse. In the Americas, mammoths, mastodons, giant ground sloths, and gomphotheres were plentiful. Each of these giants was herbivorous, relying on a daily feast of plants to keep their massive bodies working. By 10,000 years ago, the last of the Pleistocene megafauna went extinct, which led to a dramatic shifting of new world landscapes. Many plants that had relied on megafauna for dispersal went extinct, but a few — such as the avocado — squeaked by.
    < < <

    Searching for ["history of the avocado"] led to this Mar 5, 2015, "Brief History of the Avocado" ( ), which said "Archaeologists have found evidence of avocado consumption going back almost 10,000 years in central Mexico. Back then, humans were simply gathering and eating wild avocados. Researchers believe that humans began cultivating avocados about 5,000 years ago. Mesoamerican tribes like the Inca, the Olmec and the Maya grew domesticated avocado trees. In the 16th century, Spanish explorers became the first Europeans to eat avocados. Martín Fernández de Enciso (circa 1470 – 1528) was the first European to describe avocados when he mentioned them in his book (published) in 1519."

    That book was titled "Suma De Geografia Que Trata De Todas Las Partidas Del Mundo" and AbeBooks sells reproduced copies for a little over $10!! ( )

    Two informative website biographies of him: and,martin_fernandez_de.html and

    (to be cont'd in next post)

  5. Part 2:

    2) My initial search noted above also led to this entertaining article -- "The ingenious ways plants disperse their seeds" -- that includes mention and a photo of "The largest seed in the plant kingdom (which) comes from the coco-de-mer palm, native to the Seychelles Archipelago in the Indian Ocean about 1,000 miles East of Kenya. The coco-de-mer seed weighs up to 18kg but can float and is dispersed by water."

    3) Searching for [antique "botanical illustration" avocado] yielded a number of possibilities, the earliest of which were from 1849 ( ) and 1850/1 ( )

    Searching for ["first illustration" avodaco] let to documents that mentioned a number of very old books about newly discovered New World plants. If it has an illustration of the avocado, then Martín Fernández de Enciso’s "Suma geographica" (1519) would surely be the first. Other possibilities include the natural histories of Gonzalo Fernández De Oviedo y Valdes, parts of which were published as early as 1526 ("Oviedo”. Many citations of his many works are contained in this PhD thesis: )

    Now I have a question. When I'm looking for images, I run into a persistent irritant: getting Pinterest links that don't lead to the image shown in the search results. Inevitably, such searches lead (after right-clicking and choosing "View") to a Pinterest page on which (I'm guessing) many more-recent "pins" have pushed the desired image down off the page that's presented. (Or perhaps its way, way down a nearly endless scroll.)

    So my question for Dan and other expert searchers here: How do you find images (and their ultimate sources) that have been posted on Pinterest? I've often used the "minus" option to delete Pinterest pages from my image search results. But is there a way to home in on the actual image, rather than on some endless scoll of possible images?

  6. Deb and Anne here - for question 1 we first searched how do avocado trees disperse and found this article from Smithsonian Magazine. We believe this source to be credible. states that the avocado is a very old tree from the Cenozoic era when there were very large animals that would eat the entire fruit. after these animals died out it was the jaguar that continued eating the entire fruit seed included. Now the avocado depends on humans to plant the trees. Humans cultivated the tree to produce more flesh. Lots of interesting detail in this article. Who knew?
    We wanted to know more so we also looked avocado fertilization but realized almost instantly that was the wrong term we needed to use the word pollination. We got this word from one of the questions that Google posted in people also ask. One of those questions was do avocado trees need a mate. That question led to this response from the Dept. of Agriculture in Australia - seems like avocado trees have flowers and bees pollinate those flowers. Here is more from this article.
    "A mature avocado tree may produce in excess of a million flowers during the flowering period, most of which fall without producing fruit. The purpose behind the mass flowering is to encourage visits by pollen vectors. In the wild this means a range of flying and crawling insects, but in Western Australia this is believed to be mainly the European honey bee.

    The avocado has a ‘complete’ flower, but with an unusual behaviour known as ‘protogynous dichogamy’. The avocado flower has both functional male and female organs in the one flower, but opens and closes twice over a two-day period — the first day as functionally female (Figure 1) and the next as functionally male (see Figure 2). Each opening stage only lasts about half a day."

    Even Anne, a native born California girl, did not know this!

  7. Q2) For this one we brainstormed what fruits have large seeds and came up with the peach, mango and coconut. For the coconut did a search for coconut seed dispersal and found many references which said the same as this site - "The coconut seed is especially well adapted to increasing its range by the method of ocean dispersal. The seed floats when its outer layers dry out. The buoyant coconuts drift on ocean currents and end up on tropical beaches where they germinate and take root. Coconuts have traveled the seas to increase their habitat from the Malay peninsula to low-lying areas near the sea in the Caribbean, Australia, the South Sea islands, and anywhere else the temperature and rainfall lie within the coconut palm's growth parameters."
    mangoes- large primates and birds eat the fruit.

  8. Q3)for this one we did a search for early illustration avocado - did this after looking in google books and narrowing search down to first 1700-1850, then tried 1850-1900 and didn't come up with anything. Did find this result in books "Proceedings of Forty Fifth California Fruit Growers Association" on pg. 33 is an illustration of an avocado. This is from 1914. There was also a link to the wikipedia article on avocados. Found references to the first mentions of avocados. Was hoping for an illustration on the page but didn't find that but there was a reference to the sarcophagus of Pakal the great having an avocado tree on it. Found an illustration if it at this site sarcophagus of Pakal the Great avocado. So while it is isn't an illustration it is an artistic rendering of the plant. Although we don't think this was what you were looking for. But also found from this search a reference to David Fairchild. A copy of his early illustration of the avocado is found in a article This illustration dates from 9/28/05 (and that is 1905 not 2005).
    We will try to work on this some more to see if we can find older images. We did do a search in worldcat and limited the date to 18th century. We found a book in French but wasn't able to see inside to see if there was a picture.

    1. Hi Deb and Anne. Interesting about Coconut and Pakal! I'll look more into that.

      Glad Passager is back too. Hopefully,RoseMary, Fred and Luis can also share with us more often soon.

  9. Hi fellow searchers and Dan,
    For Q3 I did like all the other searchers [vintage avocado illustration], searched by date [avocado] in Google Images, books, searched for drawings, black and white illustrations, etc. but nothing was convincing (I mean old enough). I was about to give up when I wondered where I would have been searching in the pre-internet era.In a public library, a big one with very old books. In which book ? An illustrated flora.Let's go. [vintage illustrated flora] returns many examples (in images view). [vintage illustrated flora avocado] gives many images. I looked for one I thought rather old : that is followed on the same pinterest page by many others, some of them oblivioulsy coming from the same "flora". Let's search by image where this one comes from. Only 3 serp, that's good, let's peruse the pages, avoiding the pinterest ones. Bingo :
    Many illustrations from the XIXth and XXth century, some from late XVIIIth and even the drawing of an avocado tree from 1581.

    A rather complicated search : finding the good term : flora, narrowing the search to avocado, find waht I suppose to be an old illustration, search by image for the one found on pinterest,on the serps forget the pinterst pages (avoiding circling search).

    And be very lucky : I tried starting with another image of the same kind and couldn't get the site on any serp.

  10. 1. [avocado seed dispersal] finds at the wonderful: Shit You Didn't Know About Biology
    Unrepentantly celebratory insights into life on Earth's under-appreciated, under-acknowledged, and utterly amazing stories
    He calls avocado (I call it avogadro cause I eat a number of them) an Evolutionary Anachronism. Suggest its seeds were eaten by large animals now extinct; and the 'wild' avocado has less meat on it.

    And it finds "The identities of the dispersers shifted every few million years, but from an avocado’s perspective, a big mouth is a big mouth and a friendly gut is a friendly gut. The passage of a trifling 13,000 years (since the Pleistocene extinction) is too soon to exhaust the patience of genus Persea. The genes that shape fruits ideal for megafauna retain a powerful memory of an extraordinary mutualistic relationship."

    And it finds "Avocados have outpaced their evolutionary niche, which leaves them with a tough row to hoe."
    "The avocado as we know it developed to tempt the megafauna of the Cenozoic Era—massive mammals capable of gulping down an avocado whole and later, just as competently, eliminating its sizable central seed. "

    1.2 Your toast is clearly from the breadfruit tree its seeds are dispersed to bottom of the toaster.

    2. [list of large seeds] finds amongst others
    The biggest is Coco de Mer which makes no effort at dispersal the 7 year old seeds are dropped beside the mother tree and there they grow

    There are a dozen more large seeded plants which be sussed out

    3. [to search for old images] finds "Stretching half a millennium, it's amazing to see the total range of images and how the portrayals of things have changed over time. "Most of the images that are in the books are not in any of the art galleries of the world - the original copies have long ago been lost."
    The pictures range from 1500 to 1922, when copyright restrictions kick in is the source.

    Determine what the name or words were in the time frame you are after

    A tasty Challenge jon PS all our avocados are from Mexico here on Vancouver Island

  11. This comment has been removed by a blog administrator.