Stage 4: Renaissance
With the Renaissance, you will witness a cultural and scientific revolution. Upgrade your brain and metabolism to boost your productivity. Keep unlocking and upgrading body parts to reach new heights. Explore new territory and discover new resources for your human evolution.

Stage 5: Industrial Revolution
Embrace the Industrial Revolution and its technological advancements. Upgrade your brain and metabolism to increase your rate of production. Unlock body parts like the respiratory system, digestive system, and nervous system. Discover new ways to generate energy and resources for your human creation.

Stage 6: Modern Age
Enter the Modern Age, where technology and innovation are at their peak. Upgrade your brain and metabolism to boost your productivity. Unlock new body parts like the immune system and sensory organs to improve your human's abilities. Research different technologies, including robotics and artificial intelligence, to further enhance your human evolution.

Stage 7: Future
In the future stage, you will witness the ultimate evolution of the human species. Your humans will become superhumans with advanced capabilities. Upgrade your brain and metabolism to increase your production rate further. Unlock body parts like cybernetic limbs and nano-enhanced cells to make your humans even more powerful.

Challenges and Strategies:
- Time Warp: Use time warps to boost your resources production for a limited time. Use them wisely and strategically to maximize your gains.
- Research: Invest in research to unlock new abilities, resources, and technologies. Prioritize research based on your current goals and needs.
- Prestige: When you reach a certain milestone, you can choose to prestige and start over with additional bonuses. Prestige allows you to progress faster in subsequent runs.
- Upgrades: Upgrade various body parts to increase their efficiency and production. Allocate resources wisely to the parts that provide the most significant benefits.
- Achievements: Complete achievements to earn extra rewards and bonuses. Keep an eye on the achievements tab to see your progress and unlock new challenges.

Tips and Tricks:
1. Keep tapping: Tapping on the screen generates resources, so keep tapping to gather as many resources as possible.
2. Focus on efficiency: Upgrade the brain and metabolism first as these upgrades increase your overall resource production.
3. Manage your resources: Allocate resources wisely to the body parts that provide the most significant benefits. Don't overspend on unnecessary upgrades.
4. Use boosts strategically: Time warps and other boosts should be used when you need an extra push to reach a milestone or overcome a challenge.
5. Prestige at the right time: Prestige when you feel that your progress is slowing down. Starting over with additional bonuses will help you progress faster in subsequent runs.

Conclusion:
Idle Human is an addictive simulation game that allows you to create and evolve your own human species. With detailed stages, challenges, and upgrades, you will be immersed in the world of human evolution. Follow this walkthrough, use the tips and tricks, and unleash your inner scientist to create the ultimate human species!