Pleistocene Continued
Along with Devon's questions/comments posted earlier, here
are some of my ideas of topics to discuss.
1. Apparently speciation rates were very high during the
Devonian & Cariboniferous. What are biases involved with
gathering data from the fossil and pollen record? For
example, I was wondering how biases in these data could
alter our conclusions about the impacts of climate change
on rates of speciation, extinction, and species richness
patterns at different points in time. How do the
researchers account for these biases?
2. On the same topic...On p. 168 of Willas & Niklas I was
skeptical of how they claimed that high rates of
speciation were associated with extremes of climate during
the Milankovitch time scales. What could be some other
alternatives? What about asteroid impacts, key innovations
(e.g. novel adaptations that allow for huge radiations,
for ex-angiosperms), or connections of landmasses? I think
it would be interesting to talk about some of these types
of factors some more. They hardly mentioned these sorts of
topics at all in the paper.
3. Willas & Niklas say that climatic fluctuations in the
late Pliocene caused changes in community dominant species
(not species numbers), indicating that interspecific
competition was the driving force for altering the
composition of existing biomes (p. 163). In contrast, they
say that climate change in the Quaternary resulted in
reduction of species richness which apparently reflects
population migration, local extinction and isolation. What
sort of evidence led to these conclusions? What are some
alternative interpretations of the data?
4. How does "uniquely" low CO2 interacting with variations
in incoming solar radiation result in different impacts on
biotic communities during Quaternary ice ages in
comparison to previous ice ages? Is there really good
evidence for this?
5. Do you all think that using molecular genetic tools is
a good way to gather evidence for responses of species to
previous ice ages? What are some short-comings of using
these tools to estimate changes in species distributions,
population expansion/contraction, etc? Is there a way to
use molecular data of extant species to understand
evolution of ancient biota (for example, from the
Carboniferous or Devonian)..if so, how?
Just some ideas! See ya'll soon.
Brit
are some of my ideas of topics to discuss.
1. Apparently speciation rates were very high during the
Devonian & Cariboniferous. What are biases involved with
gathering data from the fossil and pollen record? For
example, I was wondering how biases in these data could
alter our conclusions about the impacts of climate change
on rates of speciation, extinction, and species richness
patterns at different points in time. How do the
researchers account for these biases?
2. On the same topic...On p. 168 of Willas & Niklas I was
skeptical of how they claimed that high rates of
speciation were associated with extremes of climate during
the Milankovitch time scales. What could be some other
alternatives? What about asteroid impacts, key innovations
(e.g. novel adaptations that allow for huge radiations,
for ex-angiosperms), or connections of landmasses? I think
it would be interesting to talk about some of these types
of factors some more. They hardly mentioned these sorts of
topics at all in the paper.
3. Willas & Niklas say that climatic fluctuations in the
late Pliocene caused changes in community dominant species
(not species numbers), indicating that interspecific
competition was the driving force for altering the
composition of existing biomes (p. 163). In contrast, they
say that climate change in the Quaternary resulted in
reduction of species richness which apparently reflects
population migration, local extinction and isolation. What
sort of evidence led to these conclusions? What are some
alternative interpretations of the data?
4. How does "uniquely" low CO2 interacting with variations
in incoming solar radiation result in different impacts on
biotic communities during Quaternary ice ages in
comparison to previous ice ages? Is there really good
evidence for this?
5. Do you all think that using molecular genetic tools is
a good way to gather evidence for responses of species to
previous ice ages? What are some short-comings of using
these tools to estimate changes in species distributions,
population expansion/contraction, etc? Is there a way to
use molecular data of extant species to understand
evolution of ancient biota (for example, from the
Carboniferous or Devonian)..if so, how?
Just some ideas! See ya'll soon.
Brit
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