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Dinofarts / Sauropod methane emissions
>From Wilkinson &c:
> ...and show that the production of the greenhouse gas methane
> by sauropods could have been an important factor in warm Mesozoic
Farting sauropods were just one part of the biosphere. An increase in
methane emissions from large sauropods might have been met by an
increase in methane-utilizing microbes (methanotrophs). The latter
are found in all sorts of environments - soils, sediments, lakes,
The net amount of methane that ends up in the atmosphere is the
difference between the amount emitted from various sources (such as
animals) and the amount consumed by methane-utilizing microbes. The
evolution of sauropod gigantism was fairly rapid on a geological scale
- but perhaps not so quick that methane-utilizing microbes couldn't
adapt. So unless it was beyond the capacity of these
methane-utilizing microbes to mop up the extra methane, the impact of
sauropod flatulence on the climate might have been minimal.
Dan Chure wrote:
> I have seen some phylogenies where Archaea is the sister group to Eukaryota,
> others where Eubacteria is the sister group to Eukaryota, and
> others where there is a trichotomy between the three groups. However, I
> think the latter is most often a byproduct of using ranks, i.e. each is a
> Domain so they must be equal. Not sure which of the first two phylogenies is
> the best supported but there are characters supporting each
> arrangement and my guess would be that there is a nested sister group
> phylogeny rather than a trichotomy.
There are two main hypotheses: (1) That Archaea and Eukarya
(=Eukaryota) are sister taxa, and form a clade to the exclusion of
Bacteria (=Eubacteria); (2) That Eukarya arose from the amalgamation
of an archaeon and a bacterium, and so is only a "secondary domain"
derived from the other two.