06 November 2005

Reader's Question

A reader asks...

Orikinla Osinachi. said...
The fossils of two copulating lovers were found recently in India dated 65 million years.

Is this scientifically possible?

Can we have fossils of our sex organs when we all know that the human male organ has no bone? And skeletons have no sex organs?
1:56 PM, November 06, 2005

That's a good question Orikinla! I haven't heard of that specific instance, and I'd love to see a link, but here's what I can say. There are two specific aspects of your question that I'd like to address: (1) humans found in India 65 million years ago; and (2) how do we know they were copulating?

To address the first part, according to scientists, the Earth and the entire Solar System were formed between 4.5 and 6.0 billion years ago. Not too long after that, around 4.0 billion years ago, life began on Earth. Photosynthesis followed 3 billion years ago (GYA), sexual reproduction was at 1.2 GYA, multi-cellular life at 1.0 GYA. Mammals emerged at least 220 million years ago (MYA), but hominids weren't until around 15 MYA, the earliest things we could possibly call human at 2 MYA, and homo sapiens at 160 to 100 thousand years ago (kYA).

So the claim of finding humans in India 65 million years ago likely is not valid. Perhaps you misread or misremembered the article, and it was really 65 thousand years ago. Perhaps it was in a disreputable source (part of why I'd like to see the actual article). Or perhaps it really was a peer reviewed scientific finding, in which case I expect to hear a lot more about it in the news, including many other scientists arguing with the group that did the work.

On to the second issue, how do we determine if fossil humans were copulating. Most of what we know about the activities of fossil remains (of other creatures too, not just humans) is circumstantial evidence. If we find a body within a house near pottery, we can guess s/he was cooking or cleaning, or maybe creating pottery. If we find a dinosaur with fossil eggs next to it, it was probably nesting and incubating the eggs. Two human bodies found in an embrace would probably be assumed to be sleeping together, but based upon position alone we probably couldn't tell if they were engaged in intercourse, we really would need evidence of sexual organs as you imply.

Most of the fossils archaeologist and paleontologists find really are bones as you state. Over time, a buried bone will become encased in other stone, and the bone itself will be replaced with other minerals forming the petrified bone. Fossilized footprints are also found, and in that process the mud the creature walked in becomes stone, and then mud of a different material is laid on top and becomes stone. These types of fossils are sometimes called trace fossils. However sometimes other materials (skin, feathers, scales, internal organs) and plant material can also fossilize. My guess there is that the body becomes incased in mud and must become fossilized quickly before the soft materials can decompose, but I am not sure. But this is how we actually know that there were a number of dinosaur species with feathers, and why some people call birds today living dinosaurs. By this method, perhaps some indication of sexual organs was fossilized and preserved

A last possibility though is just that the bodies were encased in a material and then decayed, leaving an impression of the bodies behind. The ancient Roman city of Pompeii was buried in ash after the eruption of Mt. Vesuvius on August 24, 79 C.E. A pryoclastic flow of superheated gas, ash, dust, and rocks covered the city, and the tremors also caused a tsunami in the nearby Mediterranean. The event was too fast and unexpected for the city to be evacuated, and the death of thousands allowed us an instantaneous snapshot of the city, and even what people were doing at the time.

So in order for scientists to find fossil evidence of intercourse, the couple would have had to been buried in the act, and either had the unlikely chance of being fossilized before their bodies decayed, or have left a clear shape behind. It's unlikely (which is why none have been found yet) but not impossible (which is why it'll be cool when we do, or if the story you quoted is correct).

I hope this answers your question! :)


utenzi said...

The organisms found were microscopic in size. Slime molds, I think. An organism not previously thought to be able to exchange genetic information.

zandperl said...

Thanks for the info, I'll keep my eyes peeled for an article on that and link it if I find it.

If they found 65-million-year-old sexually reproducing slime mold, that fits in with the rough outline of life on Earth that I gave, since sexual reproduction started around 1.2 billion years ago, and it's a lot more believable to me. A little less (scientifically) exciting than finding proof of two humans copulating though, and certainly less sensational. :-P

utenzi said...

True, very true. But imagine what the ID folk would say!

zandperl said...

Do you mean their outrage at finding people copulating, or at finding something, ANYTHING 65 million years old? Ooh, maybe it's Adam and Eve and they're really only 6,500 years old. ;)

utenzi said...

Both issues would infuriate them, ZP. Funny folk, they are.