The Third Canto of Shrimad Bhagavatam, where Lord Kapila (An incarnation of Krishna who appeared in Satya-yuga as the son of Devahuti and Kardama Muni) instructs His mother at least two million years ago.
Sage Kapila is the founder of Samkhya Pkilosophy.
Interstingly Samkhya does not believe in God.
He cursed and burnt to ashes the children of Sakara,after whom the Oceans get the name, Sagara, for disturbing His Meditation.
The descendant ,Bhagiratha brought the Ganges from Heavens , midst great difficulties to alleviate their suffering and have them granted Moksha….
kalalaḿ tv eka-rātreṇa pañca-rātreṇa budbudam
daśāhena tu karkandhūḥ peśy aṇḍaḿ vā tataḥ param
bhagavad purana 3-31-2
On the first night, the sperm and ovum mix, and on the fifth night the mixture ferments into a bubble. On the tenth night it develops into a form like a plum, and after that, it gradually turns into a lump of flesh or an egg, as the case may be.
māsena tu śiro dvābhyāḿ bāhv-ańghry-ādy-ańga-vigrahaḥ
nakha-lomāsthi-carmāṇi lińga-cchidrodbhavas tribhiḥ
bhagavad purana 3-31-3
In the course of a month, a head is formed, and at the end of two months the hands, feet and other limbs take shape. By the end of three months, the nails, fingers, toes, body hair, bones and skin appear, as do the organ of generation and the other apertures in the body, namely the eyes, nostrils, ears, mouth and anus.
caturbhir dhātavaḥ sapta pañcabhiḥ kṣut-tṛḍ-udbhavaḥ
ṣaḍbhir jarāyuṇā vītaḥ kukṣau bhrāmyati dakṣiṇe