Atmospheric Conditions:
1. Oxygen Levels: The oxygen content in the Earth's atmosphere during the Ordovician period was significantly lower than today's levels. The average oxygen concentration was around 15%, compared to the current 21%. This lower oxygen level would have made it difficult for humans, who are adapted to higher oxygen levels, to breathe and perform strenuous activities.
2. Carbon Dioxide Levels: The carbon dioxide levels were much higher during the Ordovician, with concentrations reaching up to 4,000 parts per million (ppm) compared to today's 415 ppm. High carbon dioxide levels can cause respiratory acidosis and impair cognitive functions in humans.
3. Global Climate: The Ordovician climate was generally warmer than today, with high sea levels and a reduced temperature gradient between the poles and the equator. This warmer climate could lead to heat stress and discomfort for humans, especially in tropical and subtropical regions.
Oceanic Conditions:
4. Marine Life: The oceans during the Ordovician were home to diverse and often gigantic marine creatures, including giant sea scorpions, enormous squid-like creatures, and large predatory fish. These creatures would have posed significant threats to human survival in terms of predation and competition for resources.
5. Anoxic Events: The Ordovician period experienced frequent anoxic events, where large areas of the ocean became depleted in oxygen. These anoxic conditions would have made it difficult for aquatic life, including humans, to survive.
Ecological Factors:
6. Flora and Fauna: The flora and fauna of the Ordovician period were vastly different from today's ecosystems. Many modern plant and animal species did not exist, and the food sources available to humans would have been limited. Adaptations to a new and unfamiliar food chain could be challenging.
7. Competition: Humans would have faced competition for resources from other species that were well-adapted to the Ordovician environment. These species would have had millions of years of evolutionary advantage over humans and could outcompete them for food and habitat.
8. Lack of Technology: Humans during the Ordovician period would not have access to the advanced technology and knowledge we possess today. Survival would be highly dependent on the basic tools and resources available during that era, making it difficult to adapt to environmental challenges.
In summary, the environmental conditions, climate, oceanic life, and ecological factors during the Ordovician period would have presented numerous obstacles to human survival. While humans have evolved to adapt to diverse environments, the challenges in the Ordovician period would have been extreme and likely insurmountable.