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38 votes

Why do wasps have "wasp waists"? What's been optimized?

Why do humans have such a flexible shoulder? Our ancestors relied on throwing things so the ones who could throw things better did better. What is the wasp's equivalent weapon? The stinger. Wasps ...
Jeremiah's user avatar
  • 859
13 votes

Why are venomous mammals and birds so rare in comparison to reptiles and fish?

Short Answer See Why do some bad traits evolve, and good ones don't? Evolution of venom is complicated and full of convergent events. Our awareness and perception of venom production is biased ...
theforestecologist's user avatar
7 votes

What are the three dots (eyes?) on the top of this wasp's head? What species might it be?

I don't know what species this is but a lot of bees and wasps have those three dots on their head. They are sort of eyes, but they can't actually make out images. They basically just detect light ...
Jeremiah's user avatar
  • 859
6 votes
Accepted

Why are my bacterial smears disappearing?

Bacteriological smears are a one-and-done scenario. Very few of them are intended for repeat use. Basically, all you can expect is that you observe it and then discard the slide. Wiping the oil off ...
bob1's user avatar
  • 12.5k
5 votes
Accepted

Why is the internal capsule dark in this transverse section of the brain?

Short answer White matter is called white matter because it is relatively white compared to gray matter. However, in fixated specimens it is not as snowy white as in textbook pictures. Background The ...
AliceD's user avatar
  • 52.5k
5 votes

What kind of tree is this — why do its huge leaves change shape and "grow fingers"?

I'm going to take a stab here. It looks a lot like Artocarpus altilis or breadfruit. However, the trunk is a bit gnarly for breadfruit, but maybe that is the result of being a street tree. Also, I ...
Bryan Hanson's user avatar
  • 1,557
5 votes

What Makes an Afrothere an Afrothere?

The word "Afrothere" comes from Latin Afer (referring to Africa) and Ancient Greek θηρίον ‎(thēríon, meaning “beast”). In other words, "Afrothere" etymologically refers to animals ...
theforestecologist's user avatar
5 votes

What is the phenomenon when animals mimic other animals in order to survive?

Deimatic display: Deimatic behaviour or startle display means any pattern of bluffing behaviour in an animal that lacks strong defences, such as suddenly displaying conspicuous eyespots, to scare off ...
Jiminy Cricket.'s user avatar
4 votes

The Perplexing Trilobite: What is the Evidence Supporting The Hypothesis That They are Not Crustaceans?

Trilobites had bodies divided into 3 lobes lengthwise. Hence the name trilobite = 3-lobed critter. The head or cephalon of the trilobite is large, nearly as broad as the body and marked by sutures. ...
Draco Freon's user avatar
4 votes
Accepted

What is the purpose of the brown louver-like structure on the underside of a mushroom?

These thin, closely-spaced structures are commonly called gills (in more formal contexts a gill is called a lamella). Our most familiar mushrooms have gills, but there are other species that do not ...
mgkrebbs's user avatar
  • 9,054
4 votes
Accepted

What is bilateral symmetry in "bilateria", an actual symmentry

You are missing that "bilateral symmetry" does not mean "the divisions are the same on some arbitrary plane" it means "the divisions are the same on one specific plane". That specific plane for ...
Bryan Krause's user avatar
  • 46.1k
4 votes

Can Eskimos be regarded a distinct species from Kalahari Bushmen based on morphological differences & geographic isolation?

I think that species delimitation is not a science, or at least not a coherent one. Different fields use different criteria, for practical or historical reasons. For instance, in plants, loads of ...
bli's user avatar
  • 2,195
4 votes
Accepted

What's the difference between a simple and 1-foliolate (unifoliolate) leaf?

Short answer: Look for a pulvinus at the leaf-stalk/leaf-lamina junction. Long Answer: So from a strictly anatomical identification standpoint, this can be a bit confusing. According to "Plant ...
theforestecologist's user avatar
4 votes

Sextuplet corn (Zea mays with branched ear)

This looks a lot like a ramosa mutant (for example see the ears in panels A,G,H - taken from Figure 2 from Gallavotti et. al. 20101). Ramosa mutations affect the branching pattern of the ...
tyersome's user avatar
  • 5,598
4 votes

Are all fibrous roots considered as adventitious roots?

Are all fibrous roots adventitious? -Yes. Take note that adventitious roots do NOT originate from a radicle (first root of a germinating seed). Adventitious roots grow primarily from the nodes of the ...
Michael B. Bibon's user avatar
4 votes

Is there a reliable method to determine if heat fixation was inadequate before proceeding with further staining steps?

I work with a teaching group who has looked at this, specifically for the aim of making things easy for undergrad labs in under-resourced countries, where gas and/or Bunsens or alcohol burners might ...
bob1's user avatar
  • 12.5k
3 votes

Twins reproducing with each other ( just hypothetical)

Monozygotic twins won't be able to reproduce (naturally), because they are of the same sex. Dizygotic twins may or may not be of the same sex, just as regular siblings; genetically speaking, they are ...
Guillaume's user avatar
  • 715
3 votes
Accepted

Why are there exactly 207 morpho-electrical types of neurons?

This is just that one author's opinion - it is telling that both sources you have for the number come from the same author. Henry Markram has a leadership role in the Blue Brain Project, a project to ...
Bryan Krause's user avatar
  • 46.1k
3 votes

Can Eskimos be regarded a distinct species from Kalahari Bushmen based on morphological differences & geographic isolation?

Welcome to the difficult concept called "Species". Let me ask a simple question are tigers and lions different species? They look different (Lion is a solid light brown. Tiger is a darker brown ...
JayCkat's user avatar
  • 2,932
3 votes

What is the purpose of the brown louver-like structure on the underside of a mushroom?

The structures you're referring to are called "lamellae" or "gills". They are coated in the spores that the fungus to reproduce. Specifically you find them on Basidiomycete and Agaricomycete fungi. ...
Joe Healey's user avatar
  • 1,301
3 votes
Accepted

What's the difference between morphospace expansion and packing?

You're almost there--both terms concern the relationship between increases in species richness and morphological diversification. They're two opposing patterns: Morphospace expansion indicates that a ...
Kara's user avatar
  • 587
3 votes

Why exactly are the reflections of sunlight in this dragonfly's eye hexagonal?

Here is the image in comments. The direction of the sun can be seen from the shadow of the left antenna. I just sketched this image to note some observations, it's the best answer that I can find at ...
bandybabboon's user avatar
  • 10.4k
3 votes

Are all fibrous roots considered as adventitious roots?

Adventitious roots are plant roots that form from any non-root tissue and are produced both during normal development and in response to stress conditions, such as flooding, nutrient deprivation, and ...
Silica19's user avatar
  • 117
3 votes

Where to find morphometric data for fish?

update: the answer below describes a database for freshwater ray-finned fish (Actineropygii), which does not cover the taxa you want (elasmobranchs are a subclass of the cartilaginous fishes, ...
Ben Bolker's user avatar
  • 5,364
3 votes
Accepted

Why isn't bacterial colony a monolayer?

As suggested by your conversation in the comments with anon, the bacterial colony is the outcome of a mechanistic growth model in which nutrient diffusion occurs from below to above. For an explicit ...
Maximilian Press's user avatar
2 votes

Can any species be bred selectively/engineered to become as diverse looking as dogs?

Not a mammal. But goldfish have also been modified both in shape and colour http://40.media.tumblr.com/ef8838366e4b7a51646b74b5330238e3/tumblr_mi60i8S52c1rmp9qqo1_1280.jpg
JayCkat's user avatar
  • 2,932
2 votes

What Makes an Afrothere an Afrothere?

@theforestecologist is right, there are very few anatomical synapomorphies (shared derived traits) if any of Afrotheria, and the few there are almost all exhibit homoplasy. But if you want obscure ...
Kara's user avatar
  • 587
2 votes

Difference between morphogens and evocators in development?

"Since the evocator Waddington and Needham discovered was ether soluble, it was considered to be a sterol, a class of molecules that includes many hormones related to later development" (https://...
Abdulrahman Binmahfuth's user avatar
2 votes
Accepted

Twins reproducing with each other ( just hypothetical)

Aside from the fact that identical twins have the same gender and thus cannot reproduce, even if we ignored that issue the offspring would not necessarily be identical to their parents, because people ...
Oosaka's user avatar
  • 3,253

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