Here is a concise summary of the text:
**Title:** The Decline of Neanderthals: A Caloric Disadvantage?
**Key Points:**
1. **Neanderthal Discovery**: In 1994, a family of Neanderthals' bones were found in El Sidrón cave, Spain, dating back to ~49,000 years ago, shortly before their extinction.
2. **Physical Characteristics**: Neanderthals were stockier, more muscular, and had a higher basal metabolic rate than Homo sapiens, requiring ~200 more calories per day.
3. **Survival Disadvantage**: When Homo sapiens arrived in Europe (~45,000 years ago), Neanderthals faced competition for similar resources, exacerbating their caloric disadvantage.
4. **Extinction Theory**: This caloric disadvantage, combined with harsh climate conditions, may have contributed to the Neanderthals' decline and eventual extinction.
5. **Evidence**: Analysis of Neanderthal bones, including signs of nutritional stress and cannibalism (e.g., El Sidrón cave, Spain), supports this theory.
**In Summary**: The Neanderthals' higher energy requirements, coupled with resource competition from Homo sapiens and harsh climate conditions, may have ultimately led to their extinction.
Here are the key facts extracted from the text, numbered and in short sentences:
**Fossil Discovery & Neanderthal Extinction**
1. In 1994, the bones of a Neanderthal family were discovered in El Sidrón cave, northwest Spain.
2. The Neanderthal remains date back to around 49,000 years ago.
3. Neanderthal remains disappear from the archaeological record a few thousand years after their deaths.
4. Neanderthals became extinct around the time early Homo sapiens arrived in Europe (circa 45,000 years ago).
**Neanderthal Characteristics**
5. Neanderthals were slightly shorter and stockier than the average Homo sapiens.
6. Neanderthal bones were shorter, thicker, and chunkier, indicating dense muscles.
7. The average Neanderthal was likely more muscular than the average human (then and now).
8. Neanderthals had adaptations for powerful sprinting rather than long-distance running.
**Metabolism & Calorie Needs**
9. Neanderthals' muscle mass suggests a higher basal metabolic rate than Homo sapiens.
10. Neanderthals likely needed around 200 more calories per day than the average human.
11. This increased calorie need would have been a significant burden over time (e.g., 3,650 extra burgers per year for a group of 10).
**Coexistence & Competition with Homo Sapiens**
12. Both Neanderthals and Homo sapiens lived in the same areas, competing for similar resources.
13. Neanderthals' higher calorie needs would have put them at a disadvantage in this competition.
14. Climate shifts in Europe around the time of Homo sapiens' arrival led to cold, dry periods, further straining resources.
**Evidence of Struggle & Cannibalism**
15. The El Sidrón Neanderthal family showed signs of nutritional stress and possible cannibalism.
16. Cut marks on their bones suggest butchering with Neanderthal-made stone tools.
17. Similar evidence of Neanderthal cannibalism has been found in France and Belgium.
**General**
18. Neanderthals thrived in their environments for hundreds of thousands of years.
19. Archaeological evidence shows similar tool technologies and behaviors between Neanderthals and ancient humans in Europe.
20. Neanderthal DNA is still present in the human genome, indicating interbreeding between the two species.