1. Alternative Viewpoints To the Standard Jared Diamond Easter Island Collapse Scenario

2. Standard Timeline

3. Revised Timeline What might the problem be here?

4. The Trees For thousands of years, most of Rapa Nui was covered with palm trees. Pollen records show that the Jubaea palm became established at least 35,000 years ago and survived a number of climatic and environmental changes. But by the time the Dutch arrived in 1722, most of these large stands of forest had disappeared. For thousands of years, most of Rapa Nui was covered with palm trees. Pollen records show that the Jubaea palm became established at least 35,000 years ago and survived a number of climatic and environmental changes. But by the time the Dutch arrived in 1722, most of these large stands of forest had disappeared.

5. Rats Ate The Trees Archaeologist J. Stephen Athens of the International Archaeological Research Institute conducted excavations on the Hawaiian Island of Oahu and found that deforestation of the Ewa Plain took place largely between 900 and 1100 A.D. but that the first evidence of human presence on this part of the island was not until about 1250 A.D. There were no climatic explanations for the disappearance of palm trees, but there was evidence that the Polynesian rat (Rattus exulans), introduced by the first human colonists, was present in the area by about 900 A.D. Athens showed that it was likely rats that deforested large areas of Oahu. Archaeologist J. Stephen Athens of the International Archaeological Research Institute conducted excavations on the Hawaiian Island of Oahu and found that deforestation of the Ewa Plain took place largely between 900 and 1100 A.D. but that the first evidence of human presence on this part of the island was not until about 1250 A.D. There were no climatic explanations for the disappearance of palm trees, but there was evidence that the Polynesian rat (Rattus exulans), introduced by the first human colonists, was present in the area by about 900 A.D. Athens showed that it was likely rats that deforested large areas of Oahu.

6. Rats are the limiting factor Previous archaeological studies, found thousands of rat bones. It seems that the Polynesian rat population grew quickly, then fell more recently before becoming extinct in the face of competition from rat species introduced by Europeans. Almost all of the palm seed shells discovered on the island show signs of having been gnawed on by rats, indicating that these once-ubiquitous rodents did affect the Jubaea palm's ability to reproduce. Previous archaeological studies, found thousands of rat bones. It seems that the Polynesian rat population grew quickly, then fell more recently before becoming extinct in the face of competition from rat species introduced by Europeans. Almost all of the palm seed shells discovered on the island show signs of having been gnawed on by rats, indicating that these once-ubiquitous rodents did affect the Jubaea palm's ability to reproduce.

7. From Benny Pesier “Together with abundant and virtually unlimited sources of seafood, the cultivation of the island’s fertile soil could easily sustain many thousands of inhabitants interminably. In view of the profusion of broadly unlimited food supplies (which also included abundant chickens, their eggs and the islands innumerable rats, a culinary ‘delicacy’ that were always available in abundance), Diamond’s notion that the natives resorted to cannibalism as a result of catastrophic mass starvation is palpably absurd. In fact, there is no archaeological evidence whatsoever for either starvation or cannibalism.”

8. Europeans or Not By 1877 EI population was down to 100 By 1877 EI population was down to 100 Diamond Scenario: Europeans not to blame Diamond Scenario: Europeans not to blame Alternative Scenario: Europeans brought disease to the 3000 inhabitants in 1772 Alternative Scenario: Europeans brought disease to the 3000 inhabitants in 1772 Prior to Europeans, deforestation was conducted in order to create agricultural fields and plant much more useful crops, like sweet potato and taro  sustainable farming Prior to Europeans, deforestation was conducted in order to create agricultural fields and plant much more useful crops, like sweet potato and taro  sustainable farming Due to its isolation, European visits after 1772 were infrequent and brief Due to its isolation, European visits after 1772 were infrequent and brief

9. Statue Obsessed? According to Thor Heyerdahl's estimates ia relatively small number of workers (six) in a relatively short period of time (a year) could produce a typical statue (Moai) working only with stone carving implements. Moreover, there is no reason to believe that a statue was carved in a single effort. The quarry on the sides of the extinct volcano holds hundreds of statues in various stages of carving, from some lightly sketched out to others all but completed. Any given statue conceivably could have been a family/clan project worked on for years. According to Thor Heyerdahl's estimates ia relatively small number of workers (six) in a relatively short period of time (a year) could produce a typical statue (Moai) working only with stone carving implements. Moreover, there is no reason to believe that a statue was carved in a single effort. The quarry on the sides of the extinct volcano holds hundreds of statues in various stages of carving, from some lightly sketched out to others all but completed. Any given statue conceivably could have been a family/clan project worked on for years.

10. Labor Intensive or Not? The traditional stories by Rapa Nui natives were that the statues "walked" to their sites. Contrarily, Jared Diamond suggests that a large statue required at least twenty carvers for a month and 500 adults for an undetermined length of time to move a large statue from the quarry lying on a wooden sled to a seaside platform. He supposes that substantial amounts of wood and rope (from woven tree bark) would be necessary for this effort. And, indeed, if that approach were the only possibility for moving the statues, it would require substantial numbers of adult laborers. On his 1955 archeological expedition, Heyerdahl demonstrated that fifteen men using four ropes in carefully choreographed sequences could "walk" a twenty-ton statue 100 yards per day. As an additional argument in favor of the walking technique, abandoned statues that have fallen on the paths to the seacoast are found face down. The traditional stories by Rapa Nui natives were that the statues "walked" to their sites. Contrarily, Jared Diamond suggests that a large statue required at least twenty carvers for a month and 500 adults for an undetermined length of time to move a large statue from the quarry lying on a wooden sled to a seaside platform. He supposes that substantial amounts of wood and rope (from woven tree bark) would be necessary for this effort. And, indeed, if that approach were the only possibility for moving the statues, it would require substantial numbers of adult laborers. On his 1955 archeological expedition, Heyerdahl demonstrated that fifteen men using four ropes in carefully choreographed sequences could "walk" a twenty-ton statue 100 yards per day. As an additional argument in favor of the walking technique, abandoned statues that have fallen on the paths to the seacoast are found face down.

11. The Soil Erosion Issue Descriptions from the first European arrivals told of remarkable soil fertility and easy crop cultivation in terraced fields, requiring little sustained effort. If there was an all-island Clan War during the final collapse years it seems unlikely that the agricultural infrastructure remained undamaged. In addition, there was little evidence of rampant soil erosion or sustained drought. Descriptions from the first European arrivals told of remarkable soil fertility and easy crop cultivation in terraced fields, requiring little sustained effort. If there was an all-island Clan War during the final collapse years it seems unlikely that the agricultural infrastructure remained undamaged. In addition, there was little evidence of rampant soil erosion or sustained drought.

12. So which Scenario is Correct Diamond over population + over resource utilization? Requires peak population of 20,000 Diamond over population + over resource utilization? Requires peak population of 20,000 Alternative sustainable farmers wiped out by introduction of European rats carrying diseases? Alternative sustainable farmers wiped out by introduction of European rats carrying diseases? Rats vs. Humans for destruction of palm trees? Rats vs. Humans for destruction of palm trees?

13. Major Unknowns When first inhabited? When first inhabited? 400 AD, 900 AD, or 1200 AD (radio carbon dating) 400 AD, 900 AD, or 1200 AD (radio carbon dating) How long did it take to make 887 statues? How long did it take to make 887 statues? Small population many decades Large population (10x) many fewer decades Was movement of statues log intensive? Rate of deforestation, slow vs. rapid? Rate of soil erosion, slow vs. rapid?

14. What About Natural Hazards Volcanic eruption  no activity for last 12,000 years Volcanic eruption  no activity for last 12,000 years Little Ice Age (1650 – 1850) could have produced long term climate change (drought) on EI; timing is about right Little Ice Age (1650 – 1850) could have produced long term climate change (drought) on EI; timing is about right One more possibility hardly considered at all but seems quite likely given what we know now One more possibility hardly considered at all but seems quite likely given what we know now

15. A Chilean Tsunami In 1960, an earthquake in Chile triggered a tidal wave, which hit the coast of Easter Island at Tongariki. The tidal wave sent the 15 Tongariki moai—some of which weigh 30 tons—several hundred feet inland. The ahu, the largest on Easter Island, was effectively destroyed. It wasn't until 1992 that the site was restored, under the direction of Chilean archaeologist, Claudio Cristino. The task took five years. In 1960, an earthquake in Chile triggered a tidal wave, which hit the coast of Easter Island at Tongariki. The tidal wave sent the 15 Tongariki moai—some of which weigh 30 tons—several hundred feet inland. The ahu, the largest on Easter Island, was effectively destroyed. It wasn't until 1992 that the site was restored, under the direction of Chilean archaeologist, Claudio Cristino. The task took five years.