A latest study led by PhD student Roi Maor from Tel Aviv University and UCL has found that mammals all over the world including Human Being, switched to daytime activity after Iridium- a very hard, silvery-white transition metal of the platinum group wiped out non-avian dinosaur about 66 million years ago.
The year-long study, conducted by Steinhardt Museum of Natural History has claimed that the predecessors of all mammals were nocturnal and increased their daytime activities only after the complete annihilation of dinosaurs, the diverse group of reptiles.
The research, appeared in Nature Ecology & Evolution has further revealed the likely activity patterns of the ancient ancestors of mammals who lived millions of years ago. According to reports, 2415 species of mammals had gone through a series of experiments after which scientists came to their conclusion. Scientists also provide information regarding different activities of different species of mammals.
"We were very surprised to find such close correlation between the disappearance of dinosaurs and the beginning of daytime activity in mammals, but we found the same result unanimously using several alternative analyses," lead author Roi Maor was quoted while talking about their findings.
The study showed that mammals like gorillas, gibbons and tamarins gave up nightlife just after the extinction of dinosaurs while the rest of the species followed them later.
"It's very difficult to relate behaviour changes in mammals that lived so long ago to ecological conditions at the time, so we can't say that the dinosaurs dying out caused mammals to start being active in the daytime. However, we see a clear correlation in our findings," said co-author Professor Kate Jones.
"We analysed a lot of data on the behaviour and ancestry of living animals for two reasons – firstly because the fossil record from that era is very limited and secondly, behaviour as a trait is very hard to infer from fossils," co-author, Professor Tamar Dayan was quoted as saying.
"You have to observe a living mammal to see if it is active at night or in the day. Fossil evidence from mammals often suggest that they were nocturnal even if they were not. Many subsequent adaptations that allow us to live in daylight are in our soft tissues," Dayan added further.
According to experts, research is still in the process and expected to detect more accurate information on the evolution process of the mammals and when their behaviour changes from night time to daytime activity.