Ancient hominins cooked fish
I can't tell you how long I've been hoping that we'd find something like this. A research team from Israel this week published their findings on the cooking of fish at a site they estimate is 780,000 years old. Zohar and colleagues show three important "ingredients" for their argument: (1) The accumulation of fish remains differs when it's a natural fish kill vs. a cultural accumulation, (2) the culturally accumulated fish remains are found in proximity to ancient hearths, and (3) the chemical structure of the remains supports moderate heating rather than burning.
The site called Gesher Benot Ya'aqov ("Daughters of Jacob Bridge," GBY) sits near the Jordan River some eight miles north of the present Sea of Galilee (yes, there's still a bridge there). It's a well known site for many reasons, especially for the appearance of Acheulean tools, stone tools associated with Homo erectus. There are also evidences of controlled burning in hearths and for the use of plant material for food (nutcracking). Physical remains of (a likely) Homo erectus are found south of the modern Sea of Galilee at a site called 'Ubeidiya.
Zohar's new paper summarized evidence of two different accumulations of fish bones at GBY. Location A had 9,200 fish remains from a number of different fish species and containing an array of bones. Location B contained mostly pharyngeal teeth (of the 30,000 fish remains discovered) from two carp species that are still known as tasty fish in the region. They note that after cooking, fish bones are modified in a way that causes them to deteriorate, so the presence of only teeth in Location B supported the idea that they were cooked. Also, the accumulation of mostly the two carps also supported the idea that something happened here to select certain fish over others.
Next, they showed that there was a significant association between known hearths and the accumulation of fish teeth in Location B. This further suggests that not only were people selecting these fish of all the ones in the nearby lake but they were bringing them to their fires.
Finally, they relied on a remarkable property of fish enameloid to nail down the idea that they were cooked instead of just happening to be near a fire where they were burned. Fish enameloid is made of tiny crystals that enlarge when you heat them, and they keep enlarging as the temperature goes up. In fresh or unheated fish, the crystals are about 14-18 nm (nanometers - there are a billion of them in one meter or 25,400,000 in an inch). When heated to 200-400 C, the crystals grew to 16.5-19.2 nm, and when cooked to 500-600 C, the crystals grew to 18-22 nm. Above 600 C (when fish are burned), the crystals got really big, 32-68 nm. At location A, the enameloid were typical of uncooked fish, but at Location B, there was a small increase in the crystal size: 14.2 - 20.7 nm. Of the 25 teeth they tested at Location B, ten of them had crystal sizes greater than 18 nm, which is only associated with moderate heating (as in cooking). And those ten teeth with crystals >18 nm were significantly closer to the hearths than the teeth with crystals <18 nm. In other words, the teeth that looked like they were cooked were nearer to the hearths than the teeth that didn't look like they were cooked. Since the teeth had a moderate increase in crystal size, they could tell that they hadn't just been thrown in the fire and burned. Somebody had to carefully control the amount of heat those fish teeth were exposed to.
Put that all together, and you have a pretty good argument for cooked fish at GBY, where stone artifacts of Homo erectus are found. Why do I care? As a creationist, I'm (obviously) interested in hominin fossils, especially in distinguishing what is and isn't human. I'd prefer to do that as holistically as possible, with different sorts of cultural evidences that affirm that they bear the image of God like we do. With Neandertals, we have lots of evidence of sophisticated tools, pigments, body ornamentation, coordinated hunting, controlled use of fire and cooking, and burying their dead. That adds up to a really good support for the humanity of Neandertals. But with other hominins, the evidence is more sparse. Thus, I've turned to studying skeletons and cluster analysis in the absence of more conclusive evidences.
Good evidence of cooked fish at GBY expands our evidence for the humanity of Homo erectus. Previously, we had evidence of tools and tool use, but direct evidence of cooking was not there. This changes things. While I can imagine monkeys smashing rocks to crack open nuts, the degree of sophistication required for cooking is not something I would associate with animals. That's a human behavior.
Thinking through the various options available for Christians, I think this new evidence continues to tip the scales in favor of the young-age creationist interpretation of a broader humanity that includes Neandertals and Homo erectus descended from Adam and Eve. Those who want to restrict "humans" to include only those made in God's image are being forced into an absurd position of asserting that humans were created not from the dust nor from ape-like ancestors but from ancestors that were virtually indistinguishable from them except that they didn't have the image of God. I find that position preposterous. The better option is clearly to just admit that "human" doesn't apply only to Homo sapiens.
Zohar et al. 2022. Evidence for the cooking of fish 780,000 years ago at Gesher Benot Ya’aqov, Israel. Nature Ecology & Evolution DOI 10.1038/s41559-022-01910-z.
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