Which species are worth saving? Which species will survive global warming? Which will thrive?
Conservationists are facing hard questions and tough decisions as they anticipate a warming climate. Some scientists are looking to the fossil record for help.
Recently, a team of paleontologists led by Alycia Stigall set out to mine the fossil record for clues as to the future challenges of conservation. Specifically, researchers wanted to know which species are most vulnerable to environmental shifts.
To find out, scientists studied the effects of significant climatic and geologic shifts on biodiversity throughout evolutionary history.
Their analysis showed ecological changes mostly benefit generalist species, while hurting specialists.
Generalists are most successful among large landmasses, where they can spread out across a variety of environs and take advantage of an array of natural resources. Specialists thrive within regions with highly differentiated habitats. Through geologic time, the division of landmasses into smaller islands promoted specialization, while the adjoining of islands into larger landmasses benefited generalists.
Because specialists occupy small ecological niches, competing for slices of a relatively small resource pie, their presence corresponds with more rapid speciation and greater biodiversity.
The fossil record suggests shifts enabling the territorial expansion of generalists coincided with a reduction in speciation and biodiversity. Given the opportunity, generalists invade the niches of specialists and diminish biodiversity.
Naturally, generalists make for the most destructive invasive species. Unfortunately, ecologists expect global warming to encourage the spread of invasive species.
The new findings — recently presented at the annual meeting of the Geological Society of America — suggest specialist species will need the most help surviving climate change.
"Places that are tropical and stable, regions that have similar climate year-round, will likely be impacted the most by invasive species," Stigall explained in a news release.
"Data sets for modern species are usually limited in terms of the number of species and years available when talking about biodiversity, so hopefully we can use the fossil record to expand our knowledge and use the past to make informed decisions about the future."
Ancient eggshell protein to help scientists study evolutionary history
Sheffield, England (UPI) Sep 27, 2016 –
New evidence suggests proteins can persist for much longer than previously thought, potentially offering scientists a deeper view of genetic history.
A team of researchers from Europe recently identified fossil proteins in a 3.8 million-year-old ostrich eggshell. The protein fragments — or others like them — could offer up genetic information 50 times older than the oldest DNA sample.
Until now, researchers assumed genetic material would be unable to survive the heat of southern Africa.
"To date, DNA analysis from frozen sediments has been able to reach back to about 700,000 years ago, but human evolution left most of its traces in Africa and the higher temperature there takes its toll on DNA preservation," lead researcher Matthew Collins, an archaeologist at the University of York, explained in a news release.
But Collins and his research partners had a theory that proteins might survive if attached to harder surfaces, like the mineral surface of an eggshell. The research team collected ancient eggshells from dig sites in Tanzania and South Africa.
"Remarkably, the oldest eggshell in the study — from the famous 3.8 million year-old site of Laetoli in Tanzania — a region of the protein was still there, giving us a unique insight into what to look for when analyzing fossils of this kind," said Colin Freeman, a materials and computer scientist at the University of Sheffield.
"Now that we know minerals can trap and preserve proteins in this way, we can be much more targeted in our study of ancient remains."
Previous research suggested the more fluid yet unstable parts of proteins govern mineral growth in eggshells, but are less likely to survive. The latest research — detailed in the journal eLife — revealed the opposite.
"As we examined older and older eggshells, we could see that this assumption was surprisingly wrong, as it was in fact the unstable regions that survived the best," said York archaeologist Beatrice Demarchi. "They were able to bind more strongly to the eggshell, allowing it be preserved in time."
Ostrich eggshells are abundant at many archaeological and palaeontological sites in Africa. Early humans used the eggshells to carry water as well as a medium for art and jewelry. Further analysis of ancient ostrich eggshell proteins could yield insights into early interactions between humans and animals.
