Does the formation of new species require a remarkable change in the environment or surroundings?
Sometimes not. In sexually reproducing organism, sometimes sexual selection can do the trick. Competition can also help, through character displacement.
There is some evidence from plant comparative genomics that a number of the main branch points in the evolution of plant biodiversity are associated with genome duplications. In other words, the offspring of a plant spontaneously doubles its genome in size and content (this happens relatively often in any case), and this offspring subsequently goes on to foster a new independent lineage. You can easily imagine that this doubling may confer a selective advantage in some cases, and that the new proto-species would soon evolve to be incompatible with its parental species due to the large difference in genomic composition, so I think, that new species have probably formed without any change in external environment.
@ Jonathan Moore: do you think this spontaneous duplication is the reason for the formation of complex organisms?
It may be one of the mechanisms for complexity to arise but I think that the reason for complexity is that the environment is complex and changing so it drives selection for complex responses from organisms.
I don't think a remarkable change in environment or surroundings is needed to give rise to a new species.
According to the biospecies concept In sexually reproducing organisms all that's needed to create a new species is a reproductive barrier. For example if one population gets sepperated they might give rise to different speicies while there are living very similar enviroments. An differenciation via ecospeicies (which by its very nature is sympathric) does not involve any huge changes in the species surroundings (excerpt those that might be triggerd by the "new" species behaviour).
All you need to get speciation is reproductive isolation. A change in the environment, or how the environment is used may play a role in this (i.e., ecological speciation). Whether or not you consider such changes 'remarkable' depends upon your opinion. Many speciation events seem to be associated with simple host shifts (e.g., the apple maggot fly speciation simply involved a switch in host from hawthornes to apples). Arctic charr can speciate many times within a single lake but they utilize the lake in very different ways (mostly along a benthic and limnetic axis). However, all you really need is something that prevents gene flow and drift should eventually result in new species (i.e., isolation by distance). Sexual selection can really speed this up in very simple ways as mentioned. The simplest example of this is small differences in color pattern resulting in speciation of many African rift-lake cichlids.
The role of gene duplication and chromosome rearrangements was once considered critical and sufficient to get speciation (no environmental changes required). Hybridization can clearly form new species (well known for angiosperms but also some common vertebrates like Rana esculenta). Michael J. D. White pushed chromosomal speciation for years. I don't know the current status of this idea. Many plant species, however, are both the products of hybridization, gene duplication, and some rearrangement. Wheat is a well studied example.
So clearly a change in the environment is not necessary for speciation. All you really need is some barrier to gene flow (behavior, phenology, sexual conflict, chromosomal architecture, etc.).
Wolves evolved into dogs by becoming scavengers of human waste. Those who could read human expressions and learned how to help humans evolved into dogs but no environmental change occurred
Most eukaryotes are not known to be sexual. There are some that argue the first eukaryote was sexual, but the evidence is very weak. And why would it have been lost in so many lineages? Until the explanation adresses the non-sexual lineages we don't have a good answer to the question in this thread. Especially that the eukatyotic ancestor and the early lineages might not have been sexual.
I agree with Sina Adl.
In non sexual, single cellular Eukaryota other things like endosymbiosis, communities and lateral gene transfere (which is more important in surch organism) play an important role.
Sometimes it is hard to adress non sexual, single cellular, organisms as individulas at all. For example how do we deal with a population that technically functions as a web, interchangeing as often as competing in evolutionary terms?
I think this is a very difficult question and no one know it for sure. I know a book written by Jerry Coyne called speciation may be useful to you
The terrestrial genetic code existed even before the earth scenario. The new specie not necessarily would make a remarkable change in the surroundings. The code existed even before of what we can consider life, or living matter. Here I share with you a recent article of my own authorship, where it demonstrates that the probability of life tends to zero than to one and it includes more details about similar topics.
Article Evolution through the stochastic dyadic Cantor Set: the uniq...
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