From Newsgroup: talk.origins

https://phys.org/news/2025-08-flamingos-reveal-secret-aging.html

This paper probably should not have been published without population
genetic data. They claim that migration extends reproductive life
expectancy by around a year and a half. The migratory population
reproduces longer.

The issue seems to be that they did not treat the populations as
distinct, probably, because they breed in the same lagoon. This
research got published in PNAS.

https://phys.org/news/2025-08-flamingos-reveal-secret-aging.html

The PNAS paper is paywalled. It may seem strange, but they did not do population genetic analysis on these flamingos.

They collected phenotypic data, but not genetic data. These are likely genetically distinct populations since sedentary breed with sedentary
and migrants breed with other migrants because sendentary birds are
together all year long, and parents lead their brood off on migration.
If they did the genetics they would likely find that they are dealing
with two populations. There would be selection for age related
phenotypes because yearling migratory birds are led by the older birds (usually their parents, and join into larger flocks), and birds learn migratory routes and stopovers from the older birds.

They are likely dealing with a genetic difference, but they didn't do
the analysis to figure it out. Their numbers are skewed and likely
subject to data collection bias. Resident breeding data was based on
1357 individuals (>90% of winter sightings in France) and only 237
individual migrant breeders (>90% of their winter sightings outside of France). They could have biased their data by considering reproductive attempts for birds that were around long enough to collect enough
sightings outside of France to be included in the analysis (they had to
have, at least 9 winter sightings outside of France).

Ron Okimoto

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From Newsgroup: talk.origins

On 8/22/2025 11:56 PM, Pro Plyd wrote:

https://arstechnica.com/science/2025/08/mammals-that-chose-ants-and- termites-as-food-almost-never-go-back/

...
A new study reveals that this extreme dietary
specialization, once thought rare and mysterious,
has emerged independently in mammals at least 12
times in the last 66 million years (i.e., since
the Cenozoic era began). This is a striking
example of convergent evolution and shows just
how powerful ants and termites have been in
shaping mammalian history.

rCLThe number of distinct origins for myrmecophagy
was certainly surprising, as was the discovery
that their origins seem to quite neatly follow
the trend of growth across ant and termite
colony sizes throughout the Cenozoic,rCY Thomas
Vida, first author of the study and a researcher
at the University of Bonn, told Ars Technica.

To figure out how often and when mammals evolved a
taste for ants and termites, the study authors first
had to track down which species are truly rCLobligate myrmecophagesrCYrCoanimals that rely entirely on ants
and termites, with little to no other food in their
diet. That meant going through nearly a centuryrCOs
worth of information. rCLWe looked through a very
large number of published natural history papers,
zoological texts, and conservation reports as a
baseline for identification,rCY Vida added.

This board dataset covered 4,099 living mammal
species. The researchers then grouped these species
into one of five dietary categories based on gut
analyses and field observations: strict ant/termite
specialists, general insect-eaters, carnivores,
omnivores, and herbivores. Next, they ran several
statistical models to work backward from this data
to reconstruct the most likely diets for each
ancestral node.

The results showed at least 12 separate origins
of obligate myrmecophagy, with instances in each
of the three main mammal groups: monotremes
(egg-laying mammals), marsupials, and placentals.
Surprisingly, some families, like Carnivora (dogs,
bears, weasels), were responsible for about a
quarter of all these origins, suggesting certain
lineages were predisposed to make the leap.
...
Once mammals switched to an ant-and-termite-only
diet, they almost never went back. The elephant
shrew genus Macroscelides was the sole exception,
shifting to omnivory after adopting myrmecophagy
during the Eocene. This suggests that such
specialization can be an evolutionary one-way
street, possibly because losing teeth and
developing highly adapted tongues, claws, and
stomachs makes it difficult to return to a
generalist diet.

rCLWe only recover a single reversal out of
specialized ant- and termite-eating, which could
mean a few things. One possibility is that it is
exceptionally difficult to re-evolve baseline
feeding features once you become heavily
specialized. It could also be that betting on
ants and termites tends to pay off, that is,
there is little selective pressure to
de-specialize given the ubiquity of social
insects in many environments,rCY Barden explained.
...

This is not really surprising. A lot of mammals are insectivores and
termites and ants are really abundant. Termites may have a biomass
greater than the current human population. There are even more ants
around. Insects are highly nutritious, and ant and termite eaters
develop the same traits because they are needed to access the ant and
termite colonies. You need digging claws and a way to slurp up as many
ants or termites as possible.

Ron Okimoto

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