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Questions tagged [speciation]

Questions pertaining to the processes by which new species arise.

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How could humans have interbred with Neanderthals if we're a different species?

To be clear, I'm not doubting that homo sapiens and homo neanderthalensis did interbreed: of that much I'm convinced. Within the past few years I've seen an upcropping of pop-sci articles discussing ...
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2answers
978 views

Have we ever observed two drosophila lineages that evolved reproductive isolation in labs?

Background The standard definition of species refers to the concept of reproductive isolation. If two lineages are found to be reproductively isolated, then we consider these two lineages to belong ...
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2answers
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Evolution in 37 years, is it possible?

I am confused, can evolution ( speciation ) really occur in such a short time ? In 1971, biologists moved five adult pairs of Italian wall lizards from their home island of Pod Kopiste, in the ...
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3answers
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Species with reproduction barriers that can both reproduce with a third species

To start with, I do not have a sound knowledge in biology or any formal education in the area. I was told that one of the definition of a species is a reproductive barrier, which means that if two ...
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3answers
267 views

How is genetic speciation defined?

What determines speciation at a molecular level? At what point does a scientist determine two lineages are different enough to be considered separate species? Does it have a margin of error?
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1answer
922 views

Can some human groups evolve into new species?

The Sentinelese people are an indigenous people of the Andaman Islands, in the Bay of Bengal, an essentially hunter-gatherer society subsisting through hunting, fishing. There is no evidence of either ...
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2answers
1k views

Why cannot there be multiple sources for same species origins?

We often associate Africa as the geographical location of the origin of humans. Why cannot there exist multiple geographic locations of origin (given same environmental conditions)? The same ...
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4answers
595 views

Extinction of species

I barely know anything about biology and realize that this might be a stupid question, but I'll ask anyway! I know that species "transform" into other species through the process of evolution. Many ...
7
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1answer
925 views

Empirical evidence for species selection

Do we have any empirical evidence in favor of species (or lineage) selection? Do we know some cases that can only be explained (or seem to be only explained) by lineage selection? What are today the ...
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2answers
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Speciation by polyploidy

Speciation can occur by polyploidy. My understanding of the process is as follows: 'polyploidy is when the number of chromosomes in an organism's cell doubles. This means that the organism has more ...
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2answers
1k views

Living intermediate species?

Hypothetical question regarding three animals 'species' {A, B, C}. Are there any examples in nature where {A and B} cannot regularly produce viable offspring, however {A and C} and {B and C} can ...
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2answers
148 views

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

I was motivated to ask based on the answer to another SE Biology Question that uses the following argument to conclude that two varients of snake are indeed a different species: To test whether [...
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1answer
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Examples of animals with different number of chromosomes that can interbreed?

When I was first started to write this question, I wanted to know how species evolve to have a different chromosomal arrangement, such as having two pairs of chromosomes instead of one? However, I ...
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2answers
317 views

Does polyploidy always isolate the polyploids from the diploid source population?

I am receiving conflicting information while researching polyploid speciation. On the one hand, some sources state that a polyploid can only reproduce sexually with polyploids having the same number ...
5
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1answer
165 views

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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3answers
951 views

Were there lifeforms before LUCA?

This question got me thinking about something. LUCA is the last universal common ancestor of all current living organisms, which is a very different definition from the first-ever living organism. Is ...
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1answer
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What is the difference between a species tree, a gene tree and a phylogenetic tree?

I have found websites and text books disagreeing over this. For example, Phylogenies are also known as “species trees”... http://biologos.org/blogs/dennis-venema-letters-to-the-duchess/evolution-...
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1answer
334 views

Definition of “structural underdominance”?

In Stathos and Fishman (2014), the authors refer to the concept of structural underdominance. The first time they mention it is in the first paragraph of the second page (left column) and the term is ...
4
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2answers
410 views

What determines the sex of hybrid offspring?

I'm aware of the usual definition of Haldane's rule, which says that, if the offspring of inter-specific hybrid offspring are sterile, then the sterile offspring will be of the heterogametic sex. That ...
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4answers
281 views

How to introduce predators to a simulated ecosystem?

I made an evolution simulator and observed that when a marginally competent predator appears, it quickly multiplies and hunts down all of the prey animals, which leads to their own extinction soon ...
4
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1answer
284 views

Are there any cases of observed extreme speciation [closed]

Is there an observed (direct not indirect) speciation on record showing a species shift within the span of history of recorded science?
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4answers
620 views

Is an egg classified based on the species inside it, or by the species that laid it?

Basically what I'm asking is if an animal of species x were to lay an egg, and the animal inside that egg happened to be the first member of a genetically new ...
3
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2answers
236 views

What proves that speciation is a pairwise process? [duplicate]

I have been asked this questions by many biology students and even non-biologist without a pretty straightforward answer to give. We are quite accustomed to phylogenetic trees where a common ancestor ...
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3answers
7k views

Definition of “Niche Complementarity”

What does "Niche Complementarity" mean? On this website they define "Niche Complementarity" as: The tendency for coexisting species which occupy a similar position along one niche dimension I don'...
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1answer
111 views

Practical Question about Evolution, Population Genetics and Speciation

North American cicada male of the genus Magicicada sing depending on the species at different times of the day and attract the females of the corresponding species. The species are very similar, but ...
3
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1answer
121 views

Speciation and Phylogeny of Lactobacillus

The lactobacillus, also called Döderlein's bacillus is a genus of facultative aerobic bacteria. There are several species such as Lactobacillus acidophillus and Lactobacillus reuteri. I have several ...
3
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1answer
81 views

Interbreedability between current humans and his ancestors

I want to know the first point of time in the past when genomes have diverged so far from modern human genomes so that they both (human and ancestors) are not interbreeadable anymore and can be seen ...
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1answer
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Cats, Dogs and Bears - how are they related?

What is the ancestral relationship between cats, dogs and bears? I presume they are more closely related to one another than other paraphyletic clades of mammal. Which came first? What did their ...
2
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1answer
372 views

Can we say that microevolution and macroevolution is fundamentally the same thing over different time scales?

This Wikipedia article states: Macroevolution is evolution on a scale of separated gene pools. Macroevolutionary studies focus on change that occurs at or above the level of species, in contrast ...
2
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1answer
130 views

How extensive was interbreeding among human species?

I have read this article about non-Africans interbreeding with Neanderthals, Neanderthals interbreeding with Denisovans, and Asians interbreeding with Denisovans as well. Now, I'm wondering what ...
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2answers
57 views

Spider identification please

Can someone tell me which spider this is please? I've found a few of them in my home in North-London, are they poisonous?
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2answers
120 views

Is there any artificial species (in particular, an artificial species of animal)?

Dogs were artificially selected from wolves, but a dog and a wolf can produce fertile offspring, and thus are of the same species. I had heard that the aurochs and cattle were different species, but I ...
2
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1answer
5k views

Speciation of humans? [duplicate]

Since we homo sapiens (and all other species) are continuously evolving, are humans undergoing speciation based on our environment? OR has there been any difference across people that could say ...
2
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1answer
110 views

Does the existence of one species imply the existence of many other?

Reading one of Sir Arthur Clarke's scifi stories, I came across a statement something to the effect of, existence of a single species automatically implies the existence of many other species. So ...
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1answer
5k views

How to read cladograms/phylograms?

I understand the difference between cladograms and phylograms; the latter can show the evolutionary linkage over time. However, I am having trouble finding out which two organisms are most closely ...
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0answers
37 views

At what point in life's history was biodiversity at its greatest?

When considering plant & animal species throughout the entire Earth, at what point in life's history was biodiversity at its greatest? The aforementioned question stems from this article about ...
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0answers
61 views

How much difference in genome is enough to prevent interbreeding? [closed]

I am not a biologist. I am a software developer interested in genetic algorithms therefore i am probably talking to biologists who also have a knowledge of genetic algorithms. I need to "breed" ...
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1answer
729 views

Are there any half-evolved animals alive today? [closed]

I know that there are animals that are "simpler" than other animals but are there any that are half-evolved? Are there any animals with half-evolved functions, like arms, legs, etc? This was part of ...
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2answers
333 views

How likely is it that Earth has millions of different species?

I know that the probability of life existing on a habitable planet is pretty slim. But, how likely is it that it hapenned millions of times in the same planet? Or was it only a few species that ...
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1answer
100 views

New speciations among Darwin's finches

In this video it is claimed that Darwin's finches arrived at Galápagos Islands just a few hundred years ago. Have there been new speciations over the past 200 years?
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1answer
120 views

How do similar environments on islands in close proximity result in allopatric speciation?

I would like to ask a question on the very classic example of allopatric speciation seen in the Galapagos finches. Adaptive radiation occurred because the finches flew from island to island, so there ...
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1answer
42 views

Genetics of Hybrids

I'm working on this problem, but I'm not sure I've done it correctly. My initial thought was that the answer was $D$, but I don't see anything in the above graph that indicated the Hybrid species is,...
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1answer
654 views

What is variation in Speciation

I read a lot about speciation. To my knowledge, a species is often defined as a group of individuals that actually or potentially interbreed in nature and produce fertile offspring. Speciation is a ...
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1answer
180 views

Systematic difference of diversity between sister taxa?

When looking broadly at the tree of life, my feeling is that, after a divergence there is almost systematically one taxon that speciates way more than the other. (There will have some approximations ...
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1answer
31 views

Which is a good methodology to find out a domestication process?

I just started with my course in genomics and I'm working with domesticated animals (cows, chickens, pigs, etc) and I would like to know which methodology is better to trace the process of ...
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0answers
48 views

How did hydrophilic plants become established on an isolated island with an arid coastal zone?

I find unconvincing the existing explanation of how several hydrophilic endemic plants became established at St Helena. This is one of the most isolated islands in the world, has an arid semi-desert ...
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3answers
2k views

How many generations does it take for one species to become a new one?

First lets consider that a species is a group of individuals that can reproduce by breeding fertile offsprings. It's usually said that evolution takes a very long time. Lets say that 1000 generations ...
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0answers
42 views

How are baselines for extinction rates established?

At the time of 2010, the UN Environment Programme estimated that 150-200 species of plant, insect, bird and mammal become extinct every 24 hours, and, that this is nearly 1000 times greater than "...
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0answers
212 views

How do I use BEAST for divergence time estimation in this case?

I am interested in using BEAST to find the divergence time estimates of species separations within a genus of frogs. The genus separated from a outgroup taxon I have chosen around 80 million years ago....
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1answer
610 views

Have scientists ever produce a new species in laboratory by means of natural selection?

I was wondering, if scientists ever produce a more complex species from a less complex species by means of natural selection? I imagine something like, bacteria which can't photosynthesis and oxygen (...