There is currently no scientific evidence to support the idea that life on Venus existed before Earth or that our ancestors migrated from Venus due to environmental changes. The prevailing scientific understanding is that life on Earth originated independently and developed over billions of years through natural processes.
While Venus is often described as Earth's "sister planet" due to its similar size and composition, the conditions on Venus are extremely inhospitable to life as we know it today. Venus has a dense atmosphere primarily composed of carbon dioxide, with surface temperatures hot enough to melt lead due to a runaway greenhouse effect. The surface pressure on Venus is about 92 times that of Earth, which creates a hostile environment with extreme temperatures and acidic conditions.
In contrast, Earth has a diverse and complex biosphere that supports a wide range of life forms. The earliest evidence of life on Earth dates back around 3.5 billion years, and through the process of evolution, life has diversified and adapted to various environments over time.
While it is theoretically possible that life could exist or have existed on Venus in the past, given the potential for different conditions in the planet's history, there is currently no conclusive evidence to support this hypothesis. The exploration of Venus remains an active area of scientific research, and future missions and studies may provide us with more insights into its past and potential for habitability.