Research Darwin's fear was unjustified? + Do human fossils in Africa bias the whole story?

[C C]

Darwin’s fear was unjustified: Writing evolutionary history by bridging the gaps
https://www.eurekalert.org/news-releases/1055619

INTRO: Fossils are used to reconstruct evolutionary history, but not all animals and plants become fossils and many fossils are destroyed before we can find them (e.g., the rocks that contain the fossils are destroyed by erosion).As a result, the fossil record has gaps and is incomplete, and we’re missing data that we need to reconstruct evolutionary history.

Now, a team of sedimentologists and stratigraphers from the Netherlands and the UK examined how this incompleteness influences the reconstruction of evolutionary history. To their surprise, they found that the incompleteness itself is actually not such a big issue. “It’s as if you are missing half of a movie. If you are missing the second half, you can’t understand the story, but if you are missing every second frame, you can still follow the plot without problems.”

“The regularity of the gaps, rather than the incompleteness itself, is what determines the reconstruction of evolutionary history,” explains Niklas Hohmann of Utrecht University’s Faculty of Geosciences, who led the study. “If a lot of data is missing, but the gaps are regular, we could still reconstruct evolutionary history without major problems, but if the gaps get too long and irregular, results are strongly biased.” (MORE - details)

PAPER: https://doi.org/10.1186/s12862-024-02287-2

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Do ancient human fossils in Africa tell the whole story, or is there a bias?
https://cosmosmagazine.com/history/archa...rica-bias/

EXCERPTS: The new statistical study, published in the journal Nature Ecology and Evolution, argues that such bias should be accounted for when archaeologists and palaeontologists try to develop an evolutionary map of human development.

“Because the evidence of early human evolution comes from a small range of sites, it’s important to acknowledge that we don’t have a complete picture of what happened across the entire continent,” says lead author W. Andrew Barr, an assistant professor of anthropology at George Washington University in the US.

“If we can point to the ways in which the fossil record is systematically biased and not a perfect representation of everything, then we can adjust our interpretations by taking this into account.”

[...] “The authors address an often overlooked but key issue in hominin evolution, spatial bias, in a clever and creative way using available primate databases and statistical analyses,” Joordens, who was not involved in the study, adds.
Beyond the rift

While scientists have long understood that the rift valley is a small sample, the authors of the new research suggest that using modern mammals reveals just how strongly the bias might be affecting current models of human evolution.

“We must avoid falling into the trap of coming up with what looks like a comprehensive reconstruction of the human story, when we know we don’t have all of the relevant evidence,” says Wood. “Imagine trying to capture the social and economic complexity of Washington, D.C., if you only had access to information from one neighbourhood. It helps if you can get a sense of how much information is missing.”

The researchers emphasise the importance of expanding archaeological digs in Africa beyond the rift valley to build a fuller picture of human evolution. (MORE - missing details)

EDIT: Ah, here's an older ad-free press release about it, complete with the paper.

Fossil hotspots in Africa obscure a more complete picture of human evolution
https://www.eurekalert.org/news-releases/1055022

[Magical Realist]

We can infer meaning even when there are gaps in sentences or number sequences. As long as the given components are suggestive enough of the next one to be able to do this. Hence for fossil transitions as well. A particular fossil may be transitional enough in itself to point to the next one even if there is a huge gap between them. The "that" of evolving is reasonably inferred. Any fossils discovered later on that fill in that gap explains the "how" of that evolving.