The London Zoo website shows the institution’s new baby Malayan tapir (Tapirus indicus), which, like all baby tapirs, is striped and spotted, looking for all the world like a mammalian watermelon:
First of all this baby, a male, needs a name. You can vote on the site above, though voting is supposed to have closed June 24. Your choices were (are) these:
I don’t understand why animals in zoos have to be given names indicative of where they come from. Why can’t we choose among, say, “Fred,” “Hugh,” “Jerry,” or “Percy”? After all, these are now British tapirs. At any rate, you can see the ultimate choice at the London Zoo Twitter feed, though I don’t think the name’s been announced.
What’s more interesting is why the babies look like watermelons. Now there are four species of tapirs, and in each case the juveniles look like the one above, but differ markedly from the color of the adults. (Drawings of adults and juveniles of the four species, and their ranges, are shown below). Since the patterns of juveniles differ slightly from each other, but are still similar, we can infer (weakly) that the pattern confers a selective advantage.
Pictures below are from the Tapir Specialist Group:
The four living species (note the juveniles):
Their distribution:
We’re not quite sure about the adaptive significance of the striking difference between adult and juvenile coloration, though I’d wager it’s an adaptation. (Maybe Larry Moran will come over and invoke genetic drift!)
In his three previous posts on tapir coloration (“How the tapir got his spots”, part I, part II, part III), Greg Mayer suggested that it’s adaptive for the young to be cryptic, perhaps because a dappled pattern hides them in vegetation (they lose this pattern at about 6 months old). But why growing tapirs do lose this pattern is unknown. Perhaps they have no requirement to be cryptic since they aren’t easily hidden in low vegetation, and are better adapted by having solid or—in the Malayan taper—harlequin coloration.
We don’t know the answer, and since it’s unlikely zoologists will go around painting over juvenile tapirs or making spots on adults, we simply have to infer from other animals, and even here we don’t know much. This is one of those questions for which the answer is in principle obtainable, but in practice is difficult—and perhaps not that interesting to zoologists.
I’m jealous of any animal with prehensile appendages. Yeah, we have the thumb, but a tail or trunk would be even cooler; a toe would be a nice addition to the thumb.
I think the cutest thing about the baby tapir is its feet. Tapirs have strange feet as it is but this strangeness is just so cute when it’s small like that.
Don’t forget the prehensile tapir penis!!!
I knew someone was going to say that! 🙂 I deliberately left it out – set you up like a straight man! 😀
like
Houdini could untie knots with his toes. Mine aren’t quite that dextrous, but I can pick up small objects with my toes and tranfer them to my hand without bending over.
Any lack of pedal dexterity in modern humans has less to do, I think, with evolutionary loss of function than with our habit of strait-jacketing our feet in pointy shoes all day.
“Any lack of pedal dexterity in modern humans has less to do, I think, with evolutionary loss of function than with our habit of strait-jacketing our feet in pointy shoes all day.”
– Greg, that is a Lamarckian example you just gave there: in other words, a trait somehow resulting from the daily life of an organism is passed on down the generations !
– Evolutionary loss due to living on the ground and bipedalism is for sure the safer bet !
Yes and favoring a foot for running over foot for climbing.
I didn’t say it was passed down; I said that our daily habits impair the dexterity of our own feet, not of our children’s feet. Nothing Lamarckian about that.
Well now that you have explained what was originally ambiguous, I disagree. I think our evolution is much more an explanation for dexterous impairment than wearing footwear.
It depends on the footwear. The mobility impairment of 19th-century Chinese women was not the result of evolution; it was the result of foot-binding.
Similarly, the difference between a couch potato and an athlete or a concert pianist is not genetic; it’s due to lack of exercise and training. Use it or lose it.
My point is that keeping your toes locked up in a box all day deprives them of opportunities for exercise and training and makes couch potatoes of them. The standard of human foot dexterity should not be measured by such people; it should be measured by people like Houdini who actually use their toes.
Greg, I invite you to read again the remark you made that I commented upon…
“Any lack of pedal dexterity in modern humans has less to do, I think, with evolutionary loss of function than with our habit of strait-jacketing our feet in pointy shoes all day.”
– lack of pedal dexterity is a clear result of our evolutionary progression. Examples of hampering of individual’s feet from the 19th century clearly do not explain the current mechanics of the human foot ! All you need do is compare a typical 19th (or earlier !) foot with your own – no/negligible difference.
– another way to illustrate this is to simply compare the foot of an Amazonian tribesman; bare-footed (no hampering/constraining AT ALL) with a high heel wearing or whatever woman.
To say any lack of pedal dexterity has less to do with our evolution than strait-jacketing is demonstrably wrong.
“looking for all the world like a mammalian watermelon”
I take it it’s been a while since you’ve seen a watermelon. 🙂
I have no idea if tapir young a sessile. But if they are, it would stand to reason that a pattern that works well as camouflage when motionless may make you more visible when on the move.
It looks like you can still vote on the website. At least, it took my choice: “budak.” About the only Malay I know is “Aku bukan budak makan pisang,” a proverb that roughly translates to “I am not a banana-eating boy” (like our “I wasn’t born yesterday” or “I didn’t just fall off the turnip truck”).
I didn’t like those name choices. I think the tapir looks more like a “Kevin”.
Kevin is an excellent name.
How about ‘Mellon’?
Or maybe Carnegie? Nice, distinguished name for the little guy…
Now I cannot decide between Nigel, Basil, Rupert, Clive and Talfryn.
Kevin
Why not a WEIT contest for a name. My
choices are Shnozzie or Snoots.
Adi
Adi
Adult pacas (rodents) and baby wild boar (suids)–roughly the same size as baby tapirs and thus benefiting from crypsis in about the same height above ground in vegetation–are also striped and spotted, consistent with an adaptive explanation for that combo in all of them.
“Since the patterns of juveniles differ slightly from each other, but are still similar, we can infer (weakly) that the pattern confers a selective advantage.”
Could you explain the logic behind that? I would have thought such similarity implies restrictions on the set of patterns that can be obtained via functional variants of the regulatory sequences involved. Why would it imply adaptation?
“We’re not quite sure about the adaptive significance of the striking difference between adult and juvenile coloration, though I’d wager it’s an adaptation.”
This strikes me as pure guesswork – I’d wager the opposite, that it’s the result of different regulatory processes, encoded by different parts of the genome, in different stages of development. Is there any reason to expect similarites between adult and juvenile coloration under (what ought to be) the default assumption of neutrality? For all we know it may be the similarities observed in some other animals that are adaptive – though I’d wager both are neutral, and that the proportion of animals displaying similarity/difference is indicative of the relative number of ways in which the similar/different scenarios can be encoded genomically.
This reminds me of Larry Moran’s recent post about jacaranda trees, or his earlier one on zebra stripes. Don’t people realize that colors matter? Spend some time in nature and you’ll quickly see how finely adjusted most animals’ colors are to their environment, and how their colors often vary within a species according to habitat in different parts of their range. This fixation on neutral explanations for major characters like hide color is armchair biology, in my opinion.
“Could you explain the logic behind that? I would have thought such similarity implies restrictions on the set of patterns that can be obtained via functional variants of the regulatory sequences involved. Why would it imply adaptation?”
We can pretty well rule out such constraints by either comparing adult coloration among species or by comparing juvenile to adult coloration within a species.
That there is some kind of constraint specifically on juvenile coloration but not on ontogenetic variation in color nor on adult coloration is possible, but, IMO, very implausible. That coloration can respond readily to selection at the within-genus or within-species scale is pretty much a universal across animals, AFAICT.
No one denies that colors can matter, or that coloration can respond to selection when it is present – this has certainly been observed. The point is it does not imply that selection (or rather, selection strong enough to make a noticeable difference) is present in every case.
In this particular case, we are _not_ dealing with variation according to habitat, so Lou’s point does not apply.
Re aspidoscelis: we are talking about constraints on juvenile coloration, so I don’t see the relevance of comparing to adult coloration (which in this case has _less_ variation, not more, though that may be due to stronger selection rather than increased constraints). I certainly did not suggest that there are no constraints on ontogenetic variation or on adult coloration – instead, the whole point is that _all_ of these are constrained in complex ways and that such constraints could in themselves explain a lot of the variation we see in nature.
Reblogged this on Mark Solock Blog.
Maybe the coloration triggers nurturing behaviors in adults.
(I.e., mommy thinks it’s cute.)
That doesn’t explain why mommy thinks that particular pattern is cute, or why mommies of different species should all think the same pattern is cute. If that were the explanation, I’d expect the patterns, like sexually-selected characters, to be highly species-specific, and for similar reasons: so mommy doesn’t waste any nurturing effort on inappropriate targets.
The best explanation seems to be that something in their shared environment favors that pattern.
which, like all baby tapirs, is striped and spotted
Someone must have placed sticks near the parents’ water trough. (Genesis chapter 30)
Wow, the range of these things is bizarre to me. According to this and Wikipedia, virtually all tapirs live[d] in the Americas. The only exception is the Malayan tapir. Does anyone have any idea how that would have occurred?
The Malayan one doesn’t appear to be an introduced population nor do there appear to be any tapirs dotting the Pacific Islands. Any ideas? Many thanks.
Look under the sections Evolution & Natural History & Genetics on the Wikipedia page: http://en.wikipedia.org/wiki/Tapir
Mammalian watermelon – I like that!
Fawns are spotted, ducklings are spotted and striped…seems to be a fairly wide-spread phenomenon. I’d suspect easily explained as breaking up the outline of the animal in question, esp. vulnerable babies.
Not all adult animals lose their spotting or stripes (zebras, giraffes). Of those that do, some of the differences, no doubt, have to do with ornamentation for attracting a mate (many ducks) being more adaptive than protective coloration.
In zebras, the stripes discourage horseflies: http://www.bbc.co.uk/nature/16944753
Maybe young tapirs or more vulnerable to parasites/predators than their parents.
It seems like it would be pretty easy to duplicate the zebra experiment.
(Or maybe their striped “pajamas” make them too darn adorable to bite.)
Wow, I’d forgotten all about that, and Jerry even posted it here!
Turing patterns is what comes to mind.
http://www.popmath.org.uk/rpamaths/rpampages/leopard.html
The relative sizes of baby and adult pelts may result in different reaction-diffusion patterns of the activators/inactivators of expression of pigment genes. Sort of explained more here in this ppt http://www.resnet.wm.edu/~jxshix/Mathbiology-1.ppt
I’ll never fully “get it” though, since I’m just a stupid biologist…
For those with an extensive interest in the natural and cultural history of tapirs (and a good knowledge of German):
http://www.4tapirs.de/
In case you are interested in literature, music, films, poems, paintings etc. featuring tapirs.
I remember when the Vancouver Aquarium’s beluga whale gave birth, they had a naming contest, which resulted in them selecting an Inuit name, ignoring the overwhelming public favorite:
Bebop.
Wild boar Sus scrofa, also have striped piglets.