Evolution refers to the observed changes in successive generations of biological organisms due to heritable components (genes and DNA). Charles Darwin proposed a major mechanism of evolution: natural selection.
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When has an organism evolved enough to be called a new species?
Imagine that we take a population of horses, split them in half and place them in completely different environments. The two species will evolve separate from each other and because the environment is ...
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Introductory books about evolution
This days I read some debates on evolution. That made me more interested to read something reliable on topic - I mean books.
I'm christian - although I think it doesn't matter on that topic - and I ...
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How many times did life emerge from the ocean?
Evolution is often mistakenly depicted as linear in popular culture. One main feature of this depiction in popular culture, but even in science popularisation, is that some ocean-dwelling animal sheds ...
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Is extreme cladism a mainstream position in the species debate?
In the philosophy of biology it has been claimed many times that a popular position regarding the question of what species are, among biologists, is cladism. For my current purposes, the defining ...
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Why *don't* all ants have wings?
Since the new queens-to-be have wings, it means that ants either evolved from insects that can fly, or insects that can fly evolved from ants, or that we have a case of parallel evolution (which is ...
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144 views
Can parents' learned traits be transmitted genetically?
I am wondering whether a behavioral trait (e.g. fear or stress experienced in the lifetime of the parent) can be transmitted genetically to its offspring?
I understand that a behavioral tendency for ...
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Why is glucose our primary source of energy?
Is there any evolutionary reason for glucose being the "main" molecule used as a source of energy, beginning with glycolysis and subsequently cellular respiration (after being converted to two ...
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Is there any reason for the variation in mitochondrial DNA size?
As my textbook An Introduction to Genetic Analysis points out, yeast mitochondrial DNA has approximately 78 kb of genetic data, while the human mitochondrial DNA contains 17 kb. Is there any evolution ...
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147 views
Computational/mathematical models for predicting phenotype from genotype
Karr, Sanghvi, et al. (2012) propose a whole-cell computational model for predicting phenotype from genotype in Mycoplasma genitalium. Their model simulates myriad cell processes such as DNA ...
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336 views
Is there an evolutionary advantage to crying when sad?
It seems as though the act of crying when sad does nothing to relieve that sadness. Is there an advantage to crying from an evolutionary perspective, or is it the end result of a different process? ...
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94 views
How and when did a dedicated immune system evolve?
I have recently been doing a lot of research into the interplay between the innate and adaptive immune systems in humans, and mammalian laboratory models. This has led to my reading some interesting ...
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110 views
Is there an “evolutionary species similarity calculator”?
Is there a website where I can input pairs of species and get an "evolutionary similarity score"?
E.g. (numbers are completely made up)
Input: Chimp and Human, Output: 97%
Input: Cat and Human, ...
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Why does the butterfly have a cocoon stage in its life cycle?
Why does the butterfly have a cocoon stage in its life cycle? It could have simply grown up within the egg/cocoon, and emerged as a butterfly. Instead it is first an egg, then a worm, then a ...
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Why is the Kakapo more attracted to humans than its own kind?
The Kakapo can be seen in this video by BBC. It is said that the species is strongly sexually attracted to humans. Why could this be the case?
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Why hasn't mother nature made us aware of our lizard brain? [closed]
In many personal improvement books I've read, people make a distinction between 2 parts of our brain:
the logical brain, dealing with logic, judgement, thinking; what makes Humans different than ...
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660 views
Why do we grow so much hair on our heads compared to our bodies?
I've been wondering about head hair, facial hair in particular. Human males can grow very extensive beards should they choose to not shave - however you do not really see this in our chimpanzee ...
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Genetic Models for Natural Selection?
My question is simple:
Given that evolution is described by random genetic mutations allowing certain members of a species to gain a reproductive advantage over others that coexist in the particular ...
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2k views
How do archaea relate to eukaryotes and bacteria?
I've read that they all share some genes, internal structure, and behaviour with each other, but with different degrees of overlap depending of what the function is. E.g., archaea have some eukaryotic ...
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63 views
Features in individuals causing high population variation
As I understand it, a population with high variation is something sought after, since it makes the population better equipped to face a dynamic environment.
Then, I guess features in an individual ...
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Why do men have nipples?
I'd be tempted to call nipples in men vestigial, but that suggests they have no modern function. They do have a function, of course, but only in women. So why do men (and all male mammals) have them?
...
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What are samples of “Outlaw Genes”
I read this in a paper
Keller and Ross describe their greenbeard gene as an ‘outlaw’.
Admittedly, the comment is only made in passing, but are they correct?
In this context an outlaw is ...
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Homologies to insect wings
All winged vertebrates have wings which are homologous to each other and to the forelimbs of the non-winged vertebrates. But what about insect wings? Are all insect wings homologous, and are there any ...
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930 views
How does Artificial Selection work?
As far as I know for evolution to work mutations are necessary. Mutations are the raw material on which natural selection works.
But mutations are always completely random and human beings have no ...
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833 views
Did animals evolve from plants?
Did animals evolve from plants? Did the animals' ancentors have chloroplasts in their cells?
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How and why did mouth and nasal cavity evolve separate?
My initial objection is that nose filters air, mouth is for eating but is used for breathing also, plus they both are used to create sounds. What is the cause and reason in this case, why do we need ...
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Why is polyploidy lethal for some organisms while for others is not?
Polyploidy is the multiplication of number of chromosomal sets from 2n to 3n (triploidy), 4n (tetraploidy) and so on. It is quite common in plants, for example many crops like wheat or Brassica forms. ...
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236 views
How does population stability evolve?
The number of individuals constituting a population is called population size. Over time population size does not remain constant, it fluctuates to different extent over generations because of ...
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What are the major evolutionary pressures for Bioluminescence?
What are the major evolutionary pressures for Bioluminescence?
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What animals stop other members of their species from mating and why?
(In particular primates)
I know chimps do. Powerful alpha males chimp would beat up omega males that they caught mating.
I know gorillas do. Powerful alpha males gorillas would beat up omega males ...
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What is the similarity between how cells organize themselves to form a human and how humans organize themselves to form a society? [closed]
Some things I have gathered.
Common properties
- individuals
- communicate
- local view
- selfish
- specialize
- organize
- replicate
- cooperate
- emergence
Terminology
cell ...
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54 views
Productive turnover and generations in the fruit fly
I was reading about the Lenski experiments on the evolution of E. coli bacterium and Dr. Elders's experiments on the evolution of the guppy.
These two experiments absolutely fascinated me, and seemed ...
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219 views
The evolution of dogs through domestication and artificial selection
I am currently reading Richard Dawkins's book 'The Greatest Show On Earth: The proof for evolution' and in the second chapter he talks very much about the evolution of dogs.
He says centuries ago ...
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Are there other mechanisms for mutation besides imperfect DNA replication?
I was reading http://www.askamathematician.com/2012/05/q-is-quantum-randomness-ever-large-enough-to-be-noticed/ and saw:
[...] the evolution of entire species can be changed by a single
mistake ...
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236 views
How does “be altruist to those who are similar to you” evolve?
There are many cases when people commit altruism. One is relationship. I am willing to die for 2 of my children or 8 nieces, say an evolutionary psychologist. Another is reciprocal altruism, which is ...
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Evolutionary origin and exogenous cues of ~28 day infradian rhythm?
The most obvious example of an approximately monthly biological cycle is the human menstrual cycle. My questions are the following:
Is it known when and where this cycle or one like it arose?
What ...
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Are there any structures in mammals that are used only by males?
There are examples of structures which only serve a purpose in females, but it seems like the opposite could also be true. Are there any structures which exist in both mammalian sexes and only serve a ...
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137 views
Did we first have swimming birds or flying birds?
Looking at the swimming birds building nests just across my garden, I suddenly wondered how evolution came to swimming birds and whether flying birds started swimming or whether swimming bird like ...
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391 views
What is the most difficult feature to explain evolutionarily? [closed]
I wonder what are examples of organs/structures/behaviours/cooperation that evolutionary biologists themselves find most difficult to explain -- to explain how they could appear evolutionarily -- ...
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How did the human brain evolve?
A common question posed is, "how did the eye evolve?", because the eye is so complex. However, this has been answered rather clearly and there are several examples around the world of animals in ...
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In which order did the cells of the immune system evolve?
Thinking about how complex the interactions between different types of immune system cells (T-helpers, T-Killers, Phagocytes, B-Cells etc.) are, it's fascinating how they all combine to get the ...
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158 views
How do we know that dinosaurs were related to lizards and/or birds?
Do we clearly know what the living closest relative of the dinosaurs are? And connected to the first question, in scientific manner how do we know these relationship between extinct species and living ...
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What advantage would the initial 'donor' in horizontal gene transfer by conjugation have received?
I am struggling to think why horizontal gene transfer between bacteria would have persisted during the course of evolution as surely it puts the 'donor' at a disadvantage?
For example, consider a ...
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Is there a dominant gene for right-handedness?
Has there been any definitive research about handedness being genetic? Also, why is right-handedness clearly dominant in humans? I'm interested in evolutionary theories, as well as any molecular ...
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Can species back-evolve?
One of the tenets of Darwin's theory is the survival of the fittest, ie adaptation of features that allow a species to adapt better to its surrounding environment. I am wondering that given the right ...
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How did viruses come to be?
My question is out of curiosity and got me thinking. How did viruses with the head, tail and tail fibres actually evolve? These viruses look more like machines than biological entities. Are there any ...
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180 views
How To Avoid Macro-Evolution Confusion? [closed]
I regularly encounter students who believe humans came from amoebas and when asked why they often say Macro-Evolution has been scientifically proven.
Macro-evolution is defined as evolution at or ...
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What do we know about LUCA?
All life on Earth (bacteria, archaea, eukarya) is thought to have evolved from a common ancestor, or last universal common ancestor (LUCA). What do we know about the characteristics of LUCA based upon ...
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134 views
What evolutionary mechanism caused felines to develop purring?
And why can some felines roar while others meow?
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231 views
Is it the case that all changes in phenotype during life are not inheritable?
This came up in a talk with a friend. I wanted to clear this doubt. I've read about it before and did again after her remark (my thoughts didn't change: her concept is Lamarck's, not Darwin's), but ...
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Are there differences in DNA between humans of today and humans from 2000 years ago?
Are there any significant differences in our genome compared to the genes of our ancestors from 1000-2000 years ago?
And if there are significant differences, do they result in significant ...
